diff --git a/.vscode/settings.json b/.vscode/settings.json
index e600f1c..3883214 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -3,7 +3,8 @@
         "decode.h": "c",
         "unity_test_module.h": "c",
         "cstdint": "c",
-        "cstdlib": "c"
+        "cstdlib": "c",
+        "stdio.h": "c"
     },
     "cmake.sourceDirectory": "/home/rens/files/T2/HC/holyc-lang/src"
 }
\ No newline at end of file
diff --git a/C/C2 AnimalShelter.zip b/C/C2 AnimalShelter.zip
index 431cf54..4912504 100644
Binary files a/C/C2 AnimalShelter.zip and b/C/C2 AnimalShelter.zip differ
diff --git a/C/C2 AnimalShelter/build/main_test b/C/C2 AnimalShelter/build/main_test
index 768bd4d..5dc4de1 100755
Binary files a/C/C2 AnimalShelter/build/main_test and b/C/C2 AnimalShelter/build/main_test differ
diff --git a/C/C2 AnimalShelter/shared/administration.c b/C/C2 AnimalShelter/shared/administration.c
index 43bd0c1..1765386 100644
--- a/C/C2 AnimalShelter/shared/administration.c	
+++ b/C/C2 AnimalShelter/shared/administration.c	
@@ -16,14 +16,13 @@ int addAnimal(const Animal* animalPtr, Animal* animalArray, size_t animalArrayLe
 }
 
 int removeAnimal(int animalId, Animal* animalArray, size_t numberOfAnimalsPresent, size_t* newNumberOfAnimalsPresent){
-    int fault = -1;
+    int fault = 0;
     size_t removedCount = 0;
     
     if (animalArray == NULL || numberOfAnimalsPresent == 0) {
-        fault = -1; // Invalid
+        return -1; // Invalid
     } else {
         size_t writeIndex = 0;
-        
         // Copy only animals that don't match the ID
         for (size_t readIndex = 0; readIndex < numberOfAnimalsPresent; ++readIndex) {
             if (animalArray[readIndex].Id != animalId) {
@@ -33,14 +32,11 @@ int removeAnimal(int animalId, Animal* animalArray, size_t numberOfAnimalsPresen
                 writeIndex++;
             } else {
                 removedCount++;
-                fault = 0;  // Found some animal(s) to remove
             }
         }
-        // Update the number of animals present
-        numberOfAnimalsPresent -= removedCount;
     }
-    
-    *newNumberOfAnimalsPresent = numberOfAnimalsPresent;
+    fault = removedCount;
+    *newNumberOfAnimalsPresent = (numberOfAnimalsPresent - removedCount);
     return fault;
 }
 
diff --git a/C/C2 AnimalShelter/test/administration_test.c b/C/C2 AnimalShelter/test/administration_test.c
index b2ffb0e..9781f19 100644
--- a/C/C2 AnimalShelter/test/administration_test.c	
+++ b/C/C2 AnimalShelter/test/administration_test.c	
@@ -18,12 +18,14 @@ const Animal originalArray[5] = {
 Animal animalArray[5];
 Animal searchArray[5];
 Animal idTestArray[5];
+Animal removeMultipleTestArray[5];
 
 void administration_setUp(void) {
     // Reset both arrays before each test
     memcpy(animalArray, originalArray, sizeof(originalArray));
     memcpy(searchArray, originalArray, sizeof(originalArray));
     memcpy(idTestArray, originalArray, sizeof(originalArray));
+    memcpy(removeMultipleTestArray, originalArray, sizeof(originalArray));
 }
 
 void administration_tearDown(void){}
@@ -31,14 +33,14 @@ void administration_tearDown(void){}
 void test_administration_remove_valid(void){
     size_t newNumberOfAnimalsPresent = 0;
     int errorCode = removeAnimal(2, animalArray, 3, &newNumberOfAnimalsPresent);
-    TEST_ASSERT_EQUAL(0, errorCode);
+    TEST_ASSERT_EQUAL(1, errorCode);
     TEST_ASSERT_EQUAL(2, newNumberOfAnimalsPresent);
 }
 
 void test_administration_remove_invalid(void){
     size_t newNumberOfAnimalsPresent = 0;
     int errorCode = removeAnimal(12, animalArray, 3, &newNumberOfAnimalsPresent);
-    TEST_ASSERT_EQUAL(-1, errorCode);
+    TEST_ASSERT_EQUAL(0, errorCode);
     TEST_ASSERT_EQUAL(3, newNumberOfAnimalsPresent);
 }
 
@@ -46,8 +48,7 @@ void test_administration_remove_multiple_of_same_id(void){
     Animal newAnimal = {.Id = 3, .Species = Dog, .Age = 3, .Sex = Male, .DateFound = {1, 1, 2023}};
     idTestArray[3] = newAnimal;
     size_t newNumberOfAnimalsPresent = 0;
-    int errorCode = removeAnimal(3, animalArray, 3, &newNumberOfAnimalsPresent);
-    TEST_ASSERT_EQUAL(0, errorCode);
+    TEST_ASSERT_EQUAL(2, removeAnimal(3, idTestArray, 4, &newNumberOfAnimalsPresent));
     TEST_ASSERT_EQUAL(2, newNumberOfAnimalsPresent);
 }
 
@@ -75,6 +76,26 @@ void test_administration_find_valid(void){
     TEST_ASSERT_EQUAL(Dog, foundAnimalV.Species);
 }
 
+
+
+void test_administration_find_xyz(void){
+    size_t newNumberOfAnimalsPresent = 0;
+    Animal animals[10] = {0};
+    animals[0].Id = 1;
+    animals[1].Id = 1;
+    animals[2].Id = 2;
+    animals[3].Id = 1;
+    animals[4].Id = 1;
+    animals[5].Id = 3;
+    animals[6].Id = 3;
+    animals[7].Id = 1;
+    animals[8].Id = 1;
+
+    TEST_ASSERT_EQUAL(6, removeAnimal(1, animals, 9, &newNumberOfAnimalsPresent));
+    TEST_ASSERT_EQUAL(3, newNumberOfAnimalsPresent);
+}
+
+
 void test_administration_find_invalid(void){
     Animal foundAnimalinV;
     int errorCode = findAnimalById(12, searchArray, 3, &foundAnimalinV);
@@ -93,6 +114,7 @@ void run_administration_tests()
     MY_RUN_TEST(test_administration_find_valid);
     MY_RUN_TEST(test_administration_find_invalid);
     MY_RUN_TEST(test_administration_remove_multiple_of_same_id);
+    MY_RUN_TEST(test_administration_find_xyz);
 
     UnityUnregisterSetupTearDown();
 }
diff --git a/C/C3 Watch.zip b/C/C3 Watch.zip
index 62728ec..120489d 100644
Binary files a/C/C3 Watch.zip and b/C/C3 Watch.zip differ
diff --git a/C/C3 Watch/build/main b/C/C3 Watch/build/main
index dfea47f..234d60d 100755
Binary files a/C/C3 Watch/build/main and b/C/C3 Watch/build/main differ
diff --git a/C/C3 Watch/build/main_test b/C/C3 Watch/build/main_test
index 1feb0e5..1124709 100755
Binary files a/C/C3 Watch/build/main_test and b/C/C3 Watch/build/main_test differ
diff --git a/C/C3 Watch/shared/watch_registers.c b/C/C3 Watch/shared/watch_registers.c
index 17136a7..f685757 100644
--- a/C/C3 Watch/shared/watch_registers.c	
+++ b/C/C3 Watch/shared/watch_registers.c	
@@ -4,103 +4,55 @@
 #include "resource_detector.h"
 
 void watch_registers_toggle_config_is_paused(uint8_t* config){
-    if (config == NULL) return;
     *config ^= 0x08; // Toggle the 4th bit 0x08 = 0b00001000
 }
 void watch_registers_set_config_time_format(uint8_t* config, time_format format){
-    uint8_t tf;
-    if (config == NULL) return;
-    if (format == TIME_HOUR_MINUTE) {
-        tf = 0x00;
-    } else if (format == TIME_HOUR_MINUTE_SECOND) {
-        tf = 0x01;
-    } 
-    *config = (*config & 0x0E) | tf;
+    *config = (*config & 0x0E) | format;
 }
 void watch_registers_set_config_time_update_interval(uint8_t* config, time_update_interval interval){
-    uint8_t mask;
-    if (config == NULL) return; 
-    if (interval == TIME_UPDATE_DISABLED){
-        mask = 0x00;
-    } else if (interval == TIME_EVERY_1_SECOND){
-        mask = 0x01;
-    } else if (interval == TIME_EVERY_30_SECONDS){
-        mask = 0x02;
-    } else if (interval == TIME_EVERY_MINUTE){
-        mask = 0x03;
-    }
-    *config = (*config & 0xF9) | (mask << 1); // Clear bits 2 and 3 and set them to the new value: 0x06 = 0b00000110
+    *config = (*config & 0xF9) | (interval << 1); // Clear bits 2 and 3 and set them to the new value: 0x06 = 0b00000110
 }
 void watch_registers_get_config_settings(uint8_t config, bool* is_paused, time_format* format, time_update_interval* interval){
-    if (format == NULL || is_paused == NULL || interval == NULL) return; //null check
-    if ((config & 0x08) != 0) {
-        *is_paused = true; // Check if the 4th bit is set
-    } else if ((config & 0x08) == 0) {
-        *is_paused = false;
-    }
-    *format = (time_format)(config & 0x01);
-    *interval = (time_update_interval)((config >> 1) & 0x03);
+    *is_paused = (config & 0x08);
+    *format = (config & 0x01);
+    *interval = ((config >> 1) & 0x03);
 }
 
 void watch_registers_set_time_hours(uint8_t* time_bits_low, uint8_t* time_bits_high, uint8_t hours){
-    if (time_bits_low == NULL || time_bits_high == NULL) return; //null check
-    if (hours > 11) {
-        hours = 11; 
-    }else if (hours < 0) {
-        hours = 0;
-    }
+    if (hours > 11) hours = 11; 
     *time_bits_high = (*time_bits_high & 0x0F) | ((hours & 0x0F) << 4); // Set the upper nibble
 }
 void watch_registers_set_time_minutes(uint8_t* time_bits_low, uint8_t* time_bits_high, uint8_t minutes){
-    if (time_bits_low == NULL || time_bits_high == NULL) return; //null check
-    if (minutes > 59) {
-        minutes = 59; 
-    } // if minutes < 0, isnt needed becouse uint8_t cannot be negative
+    if (minutes > 59) minutes = 59; 
     *time_bits_high = (*time_bits_high & 0xF0) | ((minutes >> 2) & 0x0F); // Set the lower nibble of MSB
     *time_bits_low = (*time_bits_low & 0x3F) | ((minutes & 0x03) << 6);  // Set the upper two bits of LSB
 }
 void watch_registers_set_time_seconds(uint8_t* time_bits_low, uint8_t* time_bits_high, uint8_t seconds){
-    if (time_bits_low == NULL || time_bits_high == NULL) return; //null check
-    if (seconds > 59) {
-        seconds = 59; 
-    } // if seconds < 0, isnt needed becouse uint8_t cannot be negative
+    if (seconds > 59) seconds = 59; 
     *time_bits_low = (*time_bits_low & 0xC0) | (seconds & 0x3F); // Set the lower 6 bits of LSB
 }
 void watch_registers_get_time(uint8_t time_bits_low, uint8_t time_bits_high, uint8_t* hours, uint8_t* minutes, uint8_t* seconds){
-    if (hours == NULL || minutes == NULL || seconds == NULL) return; //null check
     *hours = (time_bits_high >> 4) & 0x0F; 
     *minutes = ((time_bits_high & 0x0F) << 2) | ((time_bits_low >> 6) & 0x03); 
     *seconds = time_bits_low & 0x3F; 
 }
 
 void watch_registers_set_date_year(uint8_t* date_bits_low, uint8_t* date_bits_high, uint8_t year){
-    if (date_bits_low == NULL || date_bits_high == NULL) return; //null check
-    if (year > 127) {
-        year = 127; // Maximum year value is 127 (0x7F) for 7 bits
-    } // if year < 0, isnt needed becouse uint8_t cannot be negative
+    if (year > 127) year = 127; // Maximum year value is 127 (0x7F) for 7 bits
     *date_bits_low = (*date_bits_low & 0x80) | (year & 0x7F); // Set the lower 2 bits of LSB
 }
 void watch_registers_set_date_month(uint8_t* date_bits_low, uint8_t* date_bits_high, uint8_t month){
-    if (date_bits_low == NULL || date_bits_high == NULL) return; //null check
-    if (month > 12) {
-        month = 12; // Maximum month value is 12
-    } else if (month < 1) {
-        month = 1; // Minimum month value is 1
-    }
+    if (month > 12) month = 12; // Maximum month value is 12
+    else if (month < 1) month = 1; // Minimum month value is 1
     *date_bits_high = (*date_bits_high & 0xF8) | ((month >> 1) & 0x07); 
     *date_bits_low = (*date_bits_low & 0x7F) | ((month & 0x01) << 7); 
 }
 void watch_registers_set_date_day_of_month(uint8_t* date_bits_low, uint8_t* date_bits_high,uint8_t day_of_month){
-    if (date_bits_low == NULL || date_bits_high == NULL) return; //null check
-    if (day_of_month > 31) {
-        day_of_month = 31; // Maximum day of month value is 31
-    } else if (day_of_month < 1) {
-        day_of_month = 1; // Minimum day of month value is 1
-    }
+    if (day_of_month > 31) day_of_month = 31; // Maximum day of month value is 31
+    else if (day_of_month < 1) day_of_month = 1; // Minimum day of month value is 1
     *date_bits_high = (*date_bits_high & 0x07) | ((day_of_month & 0x1F) << 3); // Set the upper 5 bits of MSB
 }
 void watch_registers_get_date(uint8_t date_bits_low, uint8_t date_bits_high, uint8_t* year, uint8_t* month, uint8_t* day_of_month){
-    if (year == NULL || month == NULL || day_of_month == NULL) return; //null check
     *year = date_bits_low & 0x7F; // Get the lower 7 bits of LSB
     *month = ((date_bits_high & 0x07) << 1) | ((date_bits_low >> 7) & 0x01); // Get the upper 3 bits of MSB and the lower bit of LSB
     *day_of_month = (date_bits_high >> 3) & 0x1F; // Get the upper 5 bits of MSB
diff --git a/C/C3 Watch/test/watch_registers_test.c b/C/C3 Watch/test/watch_registers_test.c
index 4b76152..ae20d98 100644
--- a/C/C3 Watch/test/watch_registers_test.c	
+++ b/C/C3 Watch/test/watch_registers_test.c	
@@ -26,15 +26,15 @@ void test_setting_set_config_time_format(void){
     TEST_ASSERT_EQUAL(0x01, config); // 0b0001
 }
 void test_setting_set_config_time_update_interval(void){
-    uint8_t config = 0x00;
+    uint8_t config = 0xAA;
     watch_registers_set_config_time_update_interval(&config, TIME_UPDATE_DISABLED);
-    TEST_ASSERT_EQUAL(0x00, config); // 0b0000
+    TEST_ASSERT_EQUAL(0xA8, config); // 0b0000
     watch_registers_set_config_time_update_interval(&config, TIME_EVERY_1_SECOND);
-    TEST_ASSERT_EQUAL(0x02, config); // 0b0010
+    TEST_ASSERT_EQUAL(0xAA, config); // 0b0010
     watch_registers_set_config_time_update_interval(&config, TIME_EVERY_30_SECONDS);
-    TEST_ASSERT_EQUAL(0x04, config); // 0b0100
+    TEST_ASSERT_EQUAL(0xAC, config); // 0b0100
     watch_registers_set_config_time_update_interval(&config, TIME_EVERY_MINUTE);
-    TEST_ASSERT_EQUAL(0x06, config); // 0b0110
+    TEST_ASSERT_EQUAL(0xAE, config); // 0b0110
 }
 void test_setting_get_config_settings(void){
     uint8_t config = 0x00; // 0b00000000 so time is updated, time format hour:minute, time refresh not updated
@@ -157,29 +157,7 @@ void test_date_get_date(void){
     TEST_ASSERT_EQUAL(month, m);
     TEST_ASSERT_EQUAL(day_of_month, d);
 }
-//NULL
-void test_all_null(void){
-    watch_registers_toggle_config_is_paused(NULL);
-    watch_registers_set_config_time_format(NULL, TIME_HOUR_MINUTE);
-    watch_registers_set_config_time_update_interval(NULL, TIME_UPDATE_DISABLED);
-    watch_registers_get_config_settings(0x00, NULL, NULL, NULL);
 
-    uint8_t time_bits_low = 0;
-    uint8_t time_bits_high = 0;
-    watch_registers_set_time_hours(NULL, &time_bits_high, 0x04);
-    watch_registers_set_time_minutes(&time_bits_low, NULL, 0x30);
-    watch_registers_set_time_seconds(NULL, &time_bits_high, 0x45);
-    watch_registers_get_time(time_bits_low, time_bits_high, NULL, NULL, NULL);
-
-    uint8_t date_bits_low = 0;
-    uint8_t date_bits_high = 0;
-    watch_registers_set_date_year(NULL, &date_bits_high, 0x20);
-    watch_registers_set_date_month(&date_bits_low, NULL, 0x05);
-    watch_registers_set_date_day_of_month(NULL, &date_bits_high, 0x15);
-    watch_registers_get_date(date_bits_low, date_bits_high, NULL, NULL, NULL);
-    TEST_ASSERT_TRUE(true); // If we reach this point, the test passed
-}
-//
 //full tests
 void test_full_watch_configuration(void) {
     uint8_t config = 0x00;
@@ -225,9 +203,9 @@ void test_full_datetime_overflow_setup(void) {
     // Verify date
     uint8_t year, month, day;
     watch_registers_get_date(date_bits_low, date_bits_high, &year, &month, &day);
-    TEST_ASSERT_EQUAL(0x7F, year);  
-    TEST_ASSERT_EQUAL(0x0C, month);
-    TEST_ASSERT_EQUAL(0x1F, day); 
+    TEST_ASSERT_EQUAL(0x7F, year); // 127
+    TEST_ASSERT_EQUAL(0x0C, month); // 12
+    TEST_ASSERT_EQUAL(0x1F, day); // 31
 }
 //
 void run_watch_tests()
@@ -248,8 +226,6 @@ void run_watch_tests()
     MY_RUN_TEST(test_date_set_day_of_month);
     MY_RUN_TEST(test_date_get_date);
 
-    MY_RUN_TEST(test_all_null);
-
     MY_RUN_TEST(test_full_watch_configuration);
     MY_RUN_TEST(test_full_datetime_overflow_setup);
 
diff --git a/C/C5 and C6 Adidas/product/channel_main.c b/C/C5 and C6 Adidas/product/channel_main.c
index 1a28f3e..e67d7bf 100644
--- a/C/C5 and C6 Adidas/product/channel_main.c	
+++ b/C/C5 and C6 Adidas/product/channel_main.c	
@@ -1,9 +1,46 @@
 #include "channel.h"
-// add here includes, if needed
+#include <stdio.h>
+#include <stdbool.h>
 
 int channel_main(int argc, char* argv[])
 {
-    //add your code here
+    bool running = true;
+    FILE *input_file = fopen(argv[2], "rb");
+    if (input_file == NULL) {
+        fprintf(stderr, "Error opening input file: %s\n", argv[2]);
+        return 1;
+    }
+    FILE *output_file = fopen(argv[3], "wb");
+    if (output_file == NULL) {
+        fprintf(stderr, "Error opening output file: %s\n", argv[3]);
+        fclose(input_file);
+        return 1;
+    }
 
+    while (running){
+        // Read data 
+        unsigned char buffer[1024];
+        size_t bytes_read = fread(buffer, 1, sizeof(buffer), input_file);
+
+        if (bytes_read == 0) {
+            if (feof(input_file)) {
+                running = false; // eof reached
+            } else {
+                fprintf(stderr, "Error reading from input file\n");
+                fclose(input_file);
+                fclose(output_file);
+                return 1;
+            }
+        }
+
+        // Channel data
+        unsigned char processed_data[1024];
+        size_t processed_size = process_channel(buffer, bytes_read, processed_data);
+
+        // Write data
+        fwrite(processed_data, 1, processed_size, output_file);
+    }
+    fclose(input_file);
+    fclose(output_file);
     return 0;
 }
diff --git a/C/C5 and C6 Adidas/product/decode_main.c b/C/C5 and C6 Adidas/product/decode_main.c
index 7ed5d24..063c53a 100644
--- a/C/C5 and C6 Adidas/product/decode_main.c	
+++ b/C/C5 and C6 Adidas/product/decode_main.c	
@@ -1,10 +1,51 @@
 #include "decode.h"
-// add here includes, if needed
-
+#include <stdio.h>
+#include <stdbool.h>
 
 int decode_main(int argc, char* argv[])
 {
-    //add your code here
+    bool decoding = true;
+    FILE *input_file = fopen(argv[2], "rb");
+    if (input_file == NULL) {
+        fprintf(stderr, "Error opening input file: %s\n", argv[2]);
+        return 1;
+    }
+    FILE *output_file = fopen(argv[3], "wb");
+    if (output_file == NULL) {
+        fprintf(stderr, "Error opening output file: %s\n", argv[3]);
+        fclose(input_file);
+        return 1;
+    }
+    while (decoding)
+    {
+        // Read data 
+        unsigned char data[1024];
+        unsigned char buffer_High[sizeof(data)/2];
+        unsigned char buffer_Low[sizeof(data)/2];
+        size_t bytes_read = fread(&data, 1, sizeof(data), input_file);
+        for (size_t i = 0; i < bytes_read; i++) {
+            buffer_High[i] = data[i + (sizeof(data)/2)];
+            buffer_Low[i] = data[i];
+        }
 
+
+        if (bytes_read == 0) {
+            if (feof(input_file)) {
+                decoding = false; // eof reached
+            } else {
+                fprintf(stderr, "Error reading from input file\n");
+                fclose(input_file);
+                fclose(output_file);
+                return 1;
+            }
+        }
+
+        // Decode data
+        unsigned char decoded_data[sizeof(data)];
+        decoded_data[sizeof(data)] = decode_combine_nibbles(*buffer_High, *buffer_Low);
+        
+        // Write data
+        fwrite(decoded_data, 1, bytes_read, output_file);
+    }
     return 0;
 }
diff --git a/C/C5 and C6 Adidas/product/encode_main.c b/C/C5 and C6 Adidas/product/encode_main.c
index 85f6124..38db00a 100644
--- a/C/C5 and C6 Adidas/product/encode_main.c	
+++ b/C/C5 and C6 Adidas/product/encode_main.c	
@@ -1,10 +1,46 @@
 #include "encode.h"
-// add here includes, if needed
-
+#include <stdbool.h>
+#include <stdio.h>
 
 int encode_main(int argc, char* argv[])
 {
-    //add your code here
+    bool encoding = true;
+    FILE *input_file = fopen(argv[2], "rb");
+    if (input_file == NULL) {
+        fprintf(stderr, "Error opening input file: %s\n", argv[2]);
+        return 1;
+    }
+    FILE *output_file = fopen(argv[3], "wb");
+    if (output_file == NULL) {
+        fprintf(stderr, "Error opening output file: %s\n", argv[3]);
+        fclose(input_file);
+        return 1;
+    }
+    while (encoding)
+    {
+        // Read data 
+        unsigned char buffer[512];
+        size_t bytes_read = fread(buffer, 1, sizeof(buffer), input_file);
 
+        if (bytes_read == 0) {
+            if (feof(input_file)) {
+                encoding = false; // eof reached
+            } else {
+                fprintf(stderr, "Error reading from input file\n");
+                fclose(input_file);
+                fclose(output_file);
+                return 1;
+            }
+        }
+
+        // Encode data
+        unsigned char encoded_data_high[sizeof(buffer)];
+        unsigned char encoded_data_low[sizeof(buffer)];
+        encode_value(buffer, encoded_data_high, encoded_data_low);
+
+        // Write data
+        fwrite(encoded_data_high, 1, bytes_read, output_file);
+        fwrite(encoded_data_low, 1, bytes_read, output_file);
+    }
     return 0;
 }
diff --git a/C/C5 and C6 Adidas/shared/decode.c b/C/C5 and C6 Adidas/shared/decode.c
index 9568e05..f4f808e 100644
--- a/C/C5 and C6 Adidas/shared/decode.c	
+++ b/C/C5 and C6 Adidas/shared/decode.c	
@@ -23,7 +23,7 @@ void decode_byte(uint8_t in, uint8_t* nibble){
     // Check parity bits
     uint8_t error = 0;
     if ((p0 ^ d0 ^ d1 ^ d2) != 0) error |= 0x01;  // Error in p0 group
-    if ((p1 ^ d0 ^ d1 ^ d3) != 0) error |= 0x02;  // Error in p1 group
+    if ((p1 ^ d0 ^ d1 ^ d3) != 0) error |= 0x02;  // Error in p1 group // 0000111
     if ((p2 ^ d0 ^ d2 ^ d3) != 0) error |= 0x04;  // Error in p2 group
 
     if (MSB == 0 && error != 0) {
diff --git a/C/C6 Adidas.zip b/C/C6 Adidas.zip
deleted file mode 100644
index 986da99..0000000
Binary files a/C/C6 Adidas.zip and /dev/null differ
diff --git a/CS/CS1 PoloClubApp_RensPastoor/Club.cs b/CS/CS1 PoloClubApp_RensPastoor/Club.cs
index e3c09d0..3078c29 100644
--- a/CS/CS1 PoloClubApp_RensPastoor/Club.cs	
+++ b/CS/CS1 PoloClubApp_RensPastoor/Club.cs	
@@ -18,101 +18,107 @@ using System.Threading.Tasks;
 using System.IO;
 using System.Windows.Forms;
 
-namespace PoloClubApp {
-    class Club {
-        private string name;            // the name of the club
-        private List<Device> devices;   // a list of devices
+namespace PoloClubApp 
+{
+    /// <summary>
+    /// Represents a Polo Club that manages a collection of devices.
+    /// </summary>
+    class Club 
+    {
+        private string name;
+        private List<Device> devices;
 
-        public Club(string name){
+        /// <summary>
+        /// Initializes a new instance of the Club class.
+        /// </summary>
+        /// <param name="name">The name of the club.</param>
+        public Club(string name)
+        {
             this.name = name;
             this.devices = new List<Device>();
         }
 
-        public string Name { get { return this.name; } } // read only property for Name
+        /// <summary>
+        /// Gets the name of the club (read-only).
+        /// </summary>
+        public string Name => this.name;
 
+        // ----- Graded Methods -----
 
-        //-----Provide your answers here-----
-
-        public List<Device> GetAllWearables(){
-            List<Device> wearables = new List<Device>();
-
-            foreach (Device dev in this.devices){
-                if (dev is SmartWatch || dev is FitTracker){
-                    wearables.Add(dev);
-                }
-            }
-            return wearables;
-        }
-        public void AssignDevice(int id, string playerName){
-            Device device = GetDeviceById(id);
-
-            if(device == null){
-                throw new Exception("Device not found");
-            }
-
-            if (!(device is IWearable)){
-                device.AssignDevice(playerName, null);
-            } else {
-                IWearable wearable = (IWearable)device;
-                device.AssignDevice(playerName, wearable.GetWaterResistanceMeters());
-            }
-
-        }
-        public bool ReturnDevice(int id){
-            Device device = GetDeviceById(id);
-            return device.ReturnDevice();
+        /// <summary>
+        /// Retrieves all wearable devices (implementing IWearable interface).
+        /// </summary>
+        /// <returns>List of wearable devices.</returns>
+        public List<Device> GetAllWearables()
+        {
+            return devices.Where(d => d is IWearable).ToList();
         }
 
-        public List<Device> GetAllAssignedDevicesByPlayer(string playerName){
-            List<Device> assignedDevices = new List<Device>();
-            foreach (Device dev in this.devices){
-                if (dev.PlayerName == playerName){
-                    assignedDevices.Add(dev);
-                }
-            }
-            return assignedDevices;
+        /// <summary>
+        /// Assigns a device to a player.
+        /// </summary>
+        /// <param name="id">Device ID.</param>
+        /// <param name="playerName">Player's name.</param>
+        /// <exception cref="Exception">Thrown if device is not found.</exception>
+        public void AssignDevice(int id, string playerName)
+        {
+            var device = GetDeviceById(id) ?? throw new Exception("Device not found");
+            var waterResistance = (device as IWearable)?.GetWaterResistanceMeters();
+            device.AssignDevice(playerName, waterResistance);
         }
 
-        public List<String> GenerateReportPerPlayer(string playerName){
-            string returnString = "List of devices assigned to " + playerName;
-            List<String> lines = new List<String>();
-            List<Device> assignedDevices = GetAllAssignedDevicesByPlayer(playerName);
-
-            lines.Add(returnString);
-            string currentDeviceType = "SmartPhone";
-
-            lines.Add("Phones");
-            lines.Add("-");
-            foreach (Device dev in assignedDevices){
-                if (dev is SmartPhone){
-                    lines.Add(dev.GetDetails());
-                }
-            }
-            lines.Add("Wearables");
-            lines.Add("-");
-            foreach (Device dev in assignedDevices){
-                if (!(dev is SmartPhone)){
-                    lines.Add(dev.GetDetails());
-                }
-            }
-
-            int phoneCount = 0;
-            int wearableCount = 0;
-            foreach (Device dev in assignedDevices){
-                if (dev is SmartPhone){
-                    phoneCount++;
-                }
-                if (dev is IWearable){
-                    wearableCount++;
-                }
-            }
-
-            lines.Add("Total: " + assignedDevices.Count + " devices, " + phoneCount + " phones and " + wearableCount + " wearables");
-
-            return lines;
+        /// <summary>
+        /// Returns a device from a player.
+        /// </summary>
+        /// <param name="id">Device ID.</param>
+        /// <returns>True if successful, false if device not found.</returns>
+        public bool ReturnDevice(int id)
+        {
+            var device = GetDeviceById(id);
+            return device?.ReturnDevice() ?? false;
         }
 
+        /// <summary>
+        /// Gets all devices assigned to a specific player.
+        /// </summary>
+        /// <param name="playerName">Player's name.</param>
+        /// <returns>List of assigned devices.</returns>
+        public List<Device> GetAllAssignedDevicesByPlayer(string playerName)
+        {
+            return devices.Where(d => d.PlayerName == playerName).ToList();
+        }
 
+        /// <summary>
+        /// Generates a formatted device report for a player.
+        /// </summary>
+        /// <param name="playerName">Player's name.</param>
+        /// <returns>Formatted report lines.</returns>
+        public List<string> GenerateReportPerPlayer(string playerName)
+        {
+            var assignedDevices = GetAllAssignedDevicesByPlayer(playerName);
+            var report = new List<string>
+            {
+                $"List of devices assigned to {playerName}",
+                "Phones",
+                "-"
+            };
+
+            report.AddRange(assignedDevices
+                .OfType<SmartPhone>()
+                .Select(d => d.GetDetails()));
+
+            report.AddRange(new[] { "Wearables", "-" });
+            
+            report.AddRange(assignedDevices
+                .Where(d => d is IWearable)
+                .Select(d => d.GetDetails()));
+
+            report.Add($"Total: {assignedDevices.Count} devices, " +
+                      $"{assignedDevices.Count(d => d is SmartPhone)} phones and " +
+                      $"{assignedDevices.Count(d => d is IWearable)} wearables");
+
+            return report;
+        }
 
         // -----The provided code below will not be graded, therefore should not be changed-----
 
diff --git a/CS/CS1 PoloClubApp_RensPastoor/Device.cs b/CS/CS1 PoloClubApp_RensPastoor/Device.cs
index 7af7359..ddb282a 100644
--- a/CS/CS1 PoloClubApp_RensPastoor/Device.cs	
+++ b/CS/CS1 PoloClubApp_RensPastoor/Device.cs	
@@ -17,40 +17,81 @@ using System.Text;
 using System.Threading.Tasks;
 
 namespace PoloClubApp {
-    internal abstract class Device {
+    /// <summary>
+    /// Abstract base class representing a device in the Polo Club system.
+    /// </summary>
+    public abstract class Device {
+        /// <summary>
+        /// Gets the unique identifier of the device.
+        /// </summary>
         public int Id { get; }
+
+        /// <summary>
+        /// Gets the name of the device.
+        /// </summary>
         public string Name { get; }
+
+        /// <summary>
+        /// Gets or sets the name of the player the device is assigned to.
+        /// </summary>
         public string PlayerName { get; set; }
-        public Device(int id, string name, string playerName = null){
+
+        /// <summary>
+        /// Initializes a new instance of the Device class.
+        /// </summary>
+        /// <param name="id">The unique identifier for the device.</param>
+        /// <param name="name">The name of the device.</param>
+        /// <param name="playerName">The name of the player the device is assigned to (optional).</param>
+        protected Device(int id, string name, string playerName = null) {
             Id = id;
             Name = name;
             PlayerName = playerName;
         }
-        
+
+        /// <summary>
+        /// Gets detailed information about the device.
+        /// </summary>
+        /// <returns>Formatted string with device details.</returns>
         public abstract string GetDetails();
 
+        /// <summary>
+        /// Checks if the device is currently assigned to a player.
+        /// </summary>
+        /// <returns>True if assigned, false otherwise.</returns>
         public bool IsAssigned(){
-            return PlayerName != null;
-        }
-        public Exception AssignDevice(string playerName, int? waterResistanceMeters){
-            if (IsAssigned()){
-                throw new Exception("Device is already assigned");
-            } else if (this is IWearable && waterResistanceMeters < 3){
-                throw new Exception("Water resistance meters should be 3 or more");
-            } else if (this.Id == null){
-                throw new Exception("Device Id is null");
-            } else {
-                PlayerName = playerName;
-                return null;
-            }
+        return !string.IsNullOrEmpty(PlayerName);
         }
 
+        /// <summary>
+        /// Assigns the device to a player.
+        /// </summary>
+        /// <param name="playerName">Name of the player to assign to.</param>
+        /// <param name="waterResistanceMeters">Water resistance for wearables (nullable).</param>
+        /// <exception cref="Exception">Throws when assignment fails.</exception>
+        public void AssignDevice(string playerName, int? waterResistanceMeters)
+        {
+            if (IsAssigned())
+                throw new Exception("Device is already assigned");
+        
+            if (this is IWearable && waterResistanceMeters < 3)
+                throw new Exception("Water resistance must be 3 meters or more for wearables");
+        
+            if (Id == 0)
+                throw new Exception("Invalid device ID");
+
+            PlayerName = playerName;
+        }
+
+        /// <summary>
+        /// Returns the device from a player.
+        /// </summary>
+        /// <returns>True if successful, false if device wasn't assigned.</returns>
         public bool ReturnDevice(){
-            if (!IsAssigned()){
-                return false;
-            }
-            PlayerName = null;
-            return true;
+        if (!IsAssigned())
+            return false;
+
+        PlayerName = null;
+        return true;
         }
     }
 }
diff --git a/CS/CS1 PoloClubApp_RensPastoor/FitTracker.cs b/CS/CS1 PoloClubApp_RensPastoor/FitTracker.cs
index 2c4e038..74be842 100644
--- a/CS/CS1 PoloClubApp_RensPastoor/FitTracker.cs	
+++ b/CS/CS1 PoloClubApp_RensPastoor/FitTracker.cs	
@@ -17,27 +17,57 @@ using System.Text;
 using System.Threading.Tasks;
 
 namespace PoloClubApp {
-    internal class FitTracker : Device, IWearable {
-        public string DeviceType = "FitTracker";
-        public int Id { get; }
-        public string Name { get; }
-        public string PlayerName { get; set; }
+    /// <summary>
+    /// Represents a fitness tracker device that implements IWearable interface.
+    /// </summary>
+    public class FitTracker : Device, IWearable {
+        /// <summary>
+        /// Gets the type of the device (always "FitTracker").
+        /// </summary>
+        public string DeviceType { get; } = "FitTracker";
+
+        /// <summary>
+        /// Gets the water resistance rating in meters.
+        /// </summary>
         public int WaterResistanceMeters { get; }
+
+        /// <summary>
+        /// Gets the color of the fitness tracker.
+        /// </summary>
         public string Color { get; }
 
-        public FitTracker(int id, string name, int waterResistanceMeters, string color) : base(id, name, null){
-            Id = id;
-            Name = name;
+        /// <summary>
+        /// Initializes a new instance of the FitTracker class.
+        /// </summary>
+        /// <param name="id">The unique device identifier.</param>
+        /// <param name="name">The name of the fitness tracker.</param>
+        /// <param name="waterResistanceMeters">Water resistance rating in meters.</param>
+        /// <param name="color">The color of the device.</param>
+        public FitTracker(int id, string name, int waterResistanceMeters, string color) 
+            : base(id, name)
+        {
             WaterResistanceMeters = waterResistanceMeters;
             Color = color;
         }
 
-        public override string GetDetails(){
-            return DeviceType + "Id: " + Id + ", Name: " + Name + ", Type: " + ", WaterResistanceMeters: " + WaterResistanceMeters + ", Color: " + Color;
+        /// <summary>
+        /// Gets detailed information about the fitness tracker.
+        /// </summary>
+        /// <returns>Formatted string with device details.</returns>
+        public override string GetDetails()
+        {
+        return $"{DeviceType} - Id: {Id}, Name: {Name}, " +
+               $"Water Resistance: {WaterResistanceMeters}m, " +
+               $"Color: {Color}";
         }
 
-        public int GetWaterResistanceMeters(){
+        /// <summary>
+        /// Gets the water resistance rating.
+        /// </summary>
+        /// <returns>Water resistance in meters.</returns>
+        public int GetWaterResistanceMeters()
+        {
             return WaterResistanceMeters;
         }
-    }
+}
 }
diff --git a/CS/CS1 PoloClubApp_RensPastoor/IWearable.cs b/CS/CS1 PoloClubApp_RensPastoor/IWearable.cs
index 9c3c9dc..39b307c 100644
--- a/CS/CS1 PoloClubApp_RensPastoor/IWearable.cs	
+++ b/CS/CS1 PoloClubApp_RensPastoor/IWearable.cs	
@@ -18,8 +18,14 @@ using System.Text;
 using System.Threading.Tasks;
 
 namespace PoloClubApp {
-    interface IWearable { 
-        ///Returns the water resistance level of the wearable device in meters.
+    /// <summary>
+    /// Interface for wearable devices that have water resistance capability.
+    /// </summary>
+    public interface IWearable{
+        /// <summary>
+        /// Gets the water resistance rating of the wearable device.
+        /// </summary>
+        /// <returns>Water resistance in meters.</returns>
         int GetWaterResistanceMeters();
     }
-}
+}
\ No newline at end of file
diff --git a/CS/CS1 PoloClubApp_RensPastoor/SmartPhone.cs b/CS/CS1 PoloClubApp_RensPastoor/SmartPhone.cs
index c41421d..d3a129f 100644
--- a/CS/CS1 PoloClubApp_RensPastoor/SmartPhone.cs	
+++ b/CS/CS1 PoloClubApp_RensPastoor/SmartPhone.cs	
@@ -17,18 +17,30 @@ using System.Text;
 using System.Threading.Tasks;
 
 namespace PoloClubApp {
-    internal class SmartPhone : Device {
-        public string DeviceType = "SmartPhone";
-        public int Id { get; }
-        public string Name { get; }
-        public string PlayerName { get; set; }
-      
-        public SmartPhone(int id, string name) : base(id, name, null){
-            Id = id;
-            Name = name;
-        }
-        public override string GetDetails(){
-            return DeviceType + "Id: " + Id + ", Name: " + Name;
+    /// <summary>
+    /// Represents a smartphone device in the Polo Club system.
+    /// </summary>
+    public class SmartPhone : Device
+    {
+        /// <summary>
+        /// Gets the type of the device (always "SmartPhone").
+        /// </summary>
+        public string DeviceType { get; } = "SmartPhone";
+
+        /// <summary>
+        /// Initializes a new instance of the SmartPhone class.
+        /// </summary>
+        /// <param name="id">The unique identifier for the smartphone.</param>
+        /// <param name="name">The name of the smartphone.</param>
+        public SmartPhone(int id, string name) : base(id, name) { }
+
+        /// <summary>
+        /// Gets a formatted string with details about the smartphone.
+        /// </summary>
+        /// <returns>A string containing device details.</returns>
+        public override string GetDetails()
+        {
+            return $"{DeviceType} - Id: {Id}, Name: {Name}";
         }
     }
 }
diff --git a/CS/CS1 PoloClubApp_RensPastoor/SmartWatch.cs b/CS/CS1 PoloClubApp_RensPastoor/SmartWatch.cs
index 09a9723..a670a17 100644
--- a/CS/CS1 PoloClubApp_RensPastoor/SmartWatch.cs	
+++ b/CS/CS1 PoloClubApp_RensPastoor/SmartWatch.cs	
@@ -18,25 +18,57 @@ using System.Threading.Tasks;
 using System.Xml.Linq;
 
 namespace PoloClubApp {
-    internal class SmartWatch : Device, IWearable {
-        public string DeviceType = "Watch";
+    /// <summary>
+    /// Represents a smartwatch device that implements IWearable interface.
+    /// </summary>
+    public class SmartWatch : Device, IWearable {
+        /// <summary>
+        /// Gets the type of the device (always "SmartWatch").
+        /// </summary>
+        public string DeviceType { get; } = "SmartWatch";
+
+        /// <summary>
+        /// Gets the water resistance rating in meters.
+        /// </summary>
         public int WaterResistanceMeters { get; }
+
+        /// <summary>
+        /// Gets the screen size in millimeters.
+        /// </summary>
         public int ScreenSize { get; }
 
-        ///  Initializes a new SmartWatch with specified ID, name, player name, water resistance, and screen size.
-        public SmartWatch(int id, string name, int waterResistanceMeters, int screenSize) : base(id, name, null){
-           WaterResistanceMeters = waterResistanceMeters;
-           ScreenSize = screenSize;
+        /// <summary>
+        /// Initializes a new instance of the SmartWatch class.
+        /// </summary>
+        /// <param name="id">The unique device identifier.</param>
+        /// <param name="name">The name of the smartwatch.</param>
+        /// <param name="waterResistanceMeters">Water resistance rating in meters.</param>
+        /// <param name="screenSize">Screen size in millimeters.</param>
+        public SmartWatch(int id, string name, int waterResistanceMeters, int screenSize) 
+            : base(id, name)
+        {
+            WaterResistanceMeters = waterResistanceMeters;
+            ScreenSize = screenSize;
         }
 
-        /// Returns a string representation of the SmartWatch details.
-        public override string GetDetails(){
-            return DeviceType + "Id: " + Id + ", Name: " + Name +  ", WaterResistanceMeters: " + WaterResistanceMeters + ", ScreenSize: " + ScreenSize;
+        /// <summary>
+        /// Gets detailed information about the smartwatch.
+        /// </summary>
+        /// <returns>Formatted string with device details.</returns>
+        public override string GetDetails()
+        {
+            return $"{DeviceType} - Id: {Id}, Name: {Name}, " +
+                   $"Water Resistance: {WaterResistanceMeters}m, " +
+                   $"Screen Size: {ScreenSize}mm";
         }
 
-        /// Returns the water resistance of the SmartWatch in meters.
-        public int GetWaterResistanceMeters(){
+        /// <summary>
+        /// Gets the water resistance rating.
+        /// </summary>
+        /// <returns>Water resistance in meters.</returns>
+        public int GetWaterResistanceMeters()
+        {
             return WaterResistanceMeters;
         }
     }
-}
+}
\ No newline at end of file