diff --git a/src/hello.c b/src/hello.c
index 9d6338f..da97572 100644
--- a/src/hello.c
+++ b/src/hello.c
@@ -3,7 +3,8 @@
 
 int main(int argc, char *argv[]) {
   // This is your first C program my friend
-  printf("Hello, RTU World from C Lab in 2025!\n");
+  printf("Hello from  Murad! \n");
+  printf("Hello, RTU World from C Lab in 2025!!!!\n");
   printf("You passed %d argument(s).\n", argc - 1);
   for (int i = 1; i < argc; ++i) {
     printf("  arg[%d] = %s\n", i, argv[i]);
diff --git a/src/lab2_1 b/src/lab2_1
new file mode 100755
index 0000000..893fb3a
Binary files /dev/null and b/src/lab2_1 differ
diff --git a/src/lab2_1.c b/src/lab2_1.c
index 699339a..c3b1d32 100644
--- a/src/lab2_1.c
+++ b/src/lab2_1.c
@@ -1,3 +1,4 @@
+// Name : Murad Hashimov , id : 241ADB148
 #include <stdio.h>
 
 /*
@@ -12,17 +13,26 @@
 */
 
 int sum_to_n(int n) {
-    // TODO: implement sum with a for loop
-    return 0; // placeholder
+  int inp = 0;
+  for (int i = 1; i <= n; i++) {
+    inp = inp + i;
+  }
+  return inp;  // placeholder
 }
 
 int main(void) {
-    int n;
+  int n;
 
-    printf("Enter a positive integer n: ");
-    scanf("%d", &n);
+  printf("Enter a positive integer n: ");
+  scanf("%d", &n);
+  if (n < 1) {
+    printf("Error");
+  } else {
+    int result = sum_to_n(n);
+    printf("Result %d\n", result);
+  }
 
-    // TODO: validate input, call function, and print result
+  // TODO: validate input, call function, and print result
 
-    return 0;
+  return 0;
 }
diff --git a/src/lab2_2 b/src/lab2_2
new file mode 100755
index 0000000..316e49d
Binary files /dev/null and b/src/lab2_2 differ
diff --git a/src/lab2_2.c b/src/lab2_2.c
index d88ef6d..5ea138a 100644
--- a/src/lab2_2.c
+++ b/src/lab2_2.c
@@ -1,3 +1,5 @@
+// Name : Murad Hashimov , id : 241ADB148
+
 #include <stdio.h>
 
 /*
@@ -12,17 +14,30 @@
 */
 
 long long factorial(int n) {
-    // TODO: compute factorial iteratively
-    return 1; // placeholder
+  int a = 1;
+  int res = 1;
+
+  while (a <= n) {
+    res = res * a;
+    a++;
+  }
+  return res;  // placeholder
 }
 
 int main(void) {
-    int n;
+  int n;
+
+  printf("Enter a non-negative integer n: ");
+  scanf("%d", &n);
 
-    printf("Enter a non-negative integer n: ");
-    scanf("%d", &n);
+  if (n < 0) {
+    printf("Error , cause it is negative");
+  } else {
+    int res = factorial(n);
+    printf("Factorial of %d is %d", n, res);
+  }
 
-    // TODO: validate input, call function, print result
+  // TODO: validate input, call function, print result
 
-    return 0;
+  return 0;
 }
diff --git a/src/lab2_3.c b/src/lab2_3.c
index ddc8af6..a7d45de 100644
--- a/src/lab2_3.c
+++ b/src/lab2_3.c
@@ -1,3 +1,6 @@
+// Name : Murad Hashimov , id : 241ADB148
+
+#include <math.h>
 #include <stdio.h>
 
 /*
@@ -12,17 +15,28 @@
 */
 
 int is_prime(int n) {
-    // TODO: check if n is prime using loop up to sqrt(n)
-    return 0; // placeholder
+  for (int i = 2; i <= sqrt(n); i++) {
+    if (n % i == 0) return 0;
+  }
+
+  return 1;
 }
 
 int main(void) {
-    int n;
-
-    printf("Enter an integer n (>= 2): ");
-    scanf("%d", &n);
+  int n;
 
-    // TODO: validate input and print all primes up to n
+  printf("Enter an integer n (>= 2): ");
+  scanf("%d", &n);
 
-    return 0;
+  if (n < 2) {
+    printf("Error");
+  } else {
+    printf("Prime numbers - %d are:\n", n);
+    for (int i = 2; i <= n; i++) {
+      if (is_prime(i)) {
+        printf("%d ", i);
+      }
+    }
+  }
+  return 0;
 }
diff --git a/src/lab3_task1 b/src/lab3_task1
new file mode 100755
index 0000000..25f9889
Binary files /dev/null and b/src/lab3_task1 differ
diff --git a/src/lab3_task1.c b/src/lab3_task1.c
index f0d73ee..d88d1de 100644
--- a/src/lab3_task1.c
+++ b/src/lab3_task1.c
@@ -1,6 +1,6 @@
 /*
  * Lab 3, Task 1
- * Student Name, Student ID
+ * Murad Hashimov, 241ADB148
  *
  * Implement array algorithms:
  *   - find minimum value
@@ -21,8 +21,8 @@
  *   avg = array_avg(arr, 5); // 3.0
  */
 
-#include <stdio.h>
 #include <limits.h>
+#include <stdio.h>
 
 // Function prototypes
 int array_min(int arr[], int size);
@@ -31,40 +31,51 @@ int array_sum(int arr[], int size);
 float array_avg(int arr[], int size);
 
 int main(void) {
-    int arr[] = {10, 20, 5, 30, 15};
-    int size = 5;
+  int arr[] = {10, 20, 5, 30, 15};
+  int size = 5;
 
-    printf("Min: %d\n", array_min(arr, size));
-    printf("Max: %d\n", array_max(arr, size));
-    printf("Sum: %d\n", array_sum(arr, size));
-    printf("Avg: %.2f\n", array_avg(arr, size));
+  printf("Min: %d\n", array_min(arr, size));
+  printf("Max: %d\n", array_max(arr, size));
+  printf("Sum: %d\n", array_sum(arr, size));
+  printf("Avg: %.2f\n", array_avg(arr, size));
 
-    return 0;
+  return 0;
 }
 
 // Implement functions below
 int array_min(int arr[], int size) {
-    // TODO: return smallest element
-    int my_min = INT_MAX; //set to max infinity
-    for (int i=0;i<size;i++) {
-        if (my_min > arr[i]) {
-            my_min = arr[i];
-        }
+  int my_min = INT_MAX;
+  for (int i = 1; i < size; i++) {
+    if (arr[i] < my_min) {
+      my_min = arr[i];
     }
-    return my_min; // placeholder
+  }
+  return my_min;  // placeholder
 }
 
 int array_max(int arr[], int size) {
-    // TODO: return largest element
-    return 0; // placeholder
+  int my_max = INT_MIN;
+  for (int i = 1; i < size; i++) {
+    if (arr[i] > my_max) {
+      my_max = arr[i];
+    }
+  }
+  return my_max;  // placeholder
 }
 
 int array_sum(int arr[], int size) {
-    // TODO: return sum of elements
-    return 0; // placeholder
+  int my_sum = 0;
+  for (int i = 0; i < size; i++) {
+    my_sum = my_sum + arr[i];
+  }
+  return my_sum;  // placeholder
 }
 
 float array_avg(int arr[], int size) {
-    // TODO: return average as float
-    return 0.0f; // placeholder
+  float my_sum = 0.0;
+  for (int i = 0; i < size; i++) {
+    my_sum = my_sum + arr[i];
+  }
+  float my_avg = my_sum / size;
+  return my_avg;  // placeholder
 }
diff --git a/src/lab3_task2 b/src/lab3_task2
new file mode 100755
index 0000000..a4f632f
Binary files /dev/null and b/src/lab3_task2 differ
diff --git a/src/lab3_task2.c b/src/lab3_task2.c
index fcc50d8..8a29484 100644
--- a/src/lab3_task2.c
+++ b/src/lab3_task2.c
@@ -1,6 +1,6 @@
 /*
  * Lab 3, Task 2
- * Student Name, Student ID
+ * Murad Hashimov, 241ADB148
  *
  * Practice using pointers as function parameters.
  * Implement:
@@ -38,9 +38,11 @@ int main(void) {
 
 // Implement functions below
 void swap(int *x, int *y) {
-    // TODO: swap values using a temporary variable
+    int val = *x;
+    *x = *y;
+    *y = val;
 }
 
 void modify_value(int *x) {
-    // TODO: multiply value by 2
+    *x = (*x)*2;
 }
diff --git a/src/lab3_task3 b/src/lab3_task3
new file mode 100755
index 0000000..17163ad
Binary files /dev/null and b/src/lab3_task3 differ
diff --git a/src/lab3_task3.c b/src/lab3_task3.c
index 55cc20f..975d695 100644
--- a/src/lab3_task3.c
+++ b/src/lab3_task3.c
@@ -1,6 +1,6 @@
 /*
  * Lab 3, Task 3
- * Student Name, Student ID
+ * Murad Hashimov, 241ADB148
  *
  * Implement basic string handling functions.
  * Write your own versions of:
@@ -41,10 +41,20 @@ int main(void) {
 
 // Implement functions below
 int my_strlen(const char *str) {
-    // TODO: count characters until '\0'
-    return 0; // placeholder
+    int size = 0;
+    while(str[size] != '\0'){
+        size = size + 1;
+    }
+    return size; // placeholder
 }
 
 void my_strcpy(char *dest, const char *src) {
-    // TODO: copy characters until '\0'
+    int val = 0;
+    while (src[val]!='\0'){
+
+        dest[val] = src[val];
+
+        val++;
+    }
+    dest[val] = '\0';
 }
diff --git a/src/rfse.txt b/src/rfse.txt
new file mode 100644
index 0000000..df7cc2f
--- /dev/null
+++ b/src/rfse.txt
@@ -0,0 +1,2 @@
+Vote for Murad Hashimov! 
+RTU is top G 
diff --git a/src/student.txt b/src/student.txt
new file mode 100644
index 0000000..9f934f3
--- /dev/null
+++ b/src/student.txt
@@ -0,0 +1,3 @@
+Alice
+21
+3.75
diff --git a/src/students.txt b/src/students.txt
new file mode 100644
index 0000000..13860ff
--- /dev/null
+++ b/src/students.txt
@@ -0,0 +1,2 @@
+2425 Murad
+ 4.500000
diff --git a/src/week4_1_dynamic_array b/src/week4_1_dynamic_array
new file mode 100755
index 0000000..1187425
Binary files /dev/null and b/src/week4_1_dynamic_array differ
diff --git a/src/week4_1_dynamic_array.c b/src/week4_1_dynamic_array.c
index 575567f..e701e59 100644
--- a/src/week4_1_dynamic_array.c
+++ b/src/week4_1_dynamic_array.c
@@ -1,7 +1,7 @@
 /*
  * week4_1_dynamic_array.c
- * Author: [Your Name]
- * Student ID: [Your ID]
+ * Author: [Murad Hashimov]
+ * Student ID: [241ADB148]
  * Description:
  *   Demonstrates creation and usage of a dynamic array using malloc.
  *   Students should allocate memory for an integer array, fill it with data,
@@ -12,6 +12,7 @@
 #include <stdlib.h>
 
 int main(void) {
+    int summ;
     int n;
     int *arr = NULL;
 
@@ -22,17 +23,37 @@ int main(void) {
     }
 
     // TODO: Allocate memory for n integers using malloc
+    arr = malloc(n * sizeof(int));
     // Example: arr = malloc(n * sizeof(int));
 
     // TODO: Check allocation success
+    if (arr == 0) {
+        printf("\nMemory allocation is false!");
+        return 1;
+    }
 
     // TODO: Read n integers from user input and store in array
-
+    printf("Put %d integers into array - \n", n);
+    for (int i = 0; i < n; i++) {
+        if (scanf("%d", &arr[i]) != 1) {
+            printf("Invalid input.\n");
+            free(arr);
+            return 1;
+        }
+    }
     // TODO: Compute sum and average
+    for (int i = 0; i < n; i++) {
+        summ = summ + arr[i];
+    }
+    float average = (float)summ / n;
 
     // TODO: Print the results
+    printf("The sum of values - %d \n", summ);
+
+    printf("The average of values - %f \n", average);
 
     // TODO: Free allocated memory
+    free(arr);
 
     return 0;
 }
diff --git a/src/week4_2_struct_student b/src/week4_2_struct_student
new file mode 100755
index 0000000..f2da187
Binary files /dev/null and b/src/week4_2_struct_student differ
diff --git a/src/week4_2_struct_student.c b/src/week4_2_struct_student.c
index b04fc32..3825507 100644
--- a/src/week4_2_struct_student.c
+++ b/src/week4_2_struct_student.c
@@ -1,7 +1,7 @@
 /*
  * week4_2_struct_student.c
- * Author: [Your Name]
- * Student ID: [Your ID]
+ * Author: [Murad Hashimov]
+ * Student ID: [241ADB148]
  * Description:
  *   Demonstrates defining and using a struct in C.
  *   Students should define a 'Student' struct with fields like name, id, and grade.
@@ -13,18 +13,32 @@
 
 // TODO: Define struct Student with fields: name (char[]), id (int), grade (float)
 // Example:
-// struct Student {
-//     char name[50];
-//     int id;
-//     float grade;
-// };
+struct Student {
+    char name[50];
+    int id;
+    float grade;
+};
 
 int main(void) {
+    struct Student student_1;
+
+    struct Student student_2;
+
     // TODO: Declare one or more Student variables
+    strcpy(student_1.name, "Murad Hashimov");  
+    student_1.id = 241148;
+    student_1.grade = 80.0;
 
-    // TODO: Assign values (either manually or via scanf)
+    // student_2
+    strcpy(student_2.name, "Bombo Clad");
+    student_2.id = 241567;
+    student_2.grade = 95;
 
-    // TODO: Print struct contents using printf
+    
+    printf("Student 1: Name: %s\n, ID: %d\n, Grade: %f\n", student_1.name, student_1.id, student_1.grade);
+    //
+    printf("Student 2: Name: %s\n, ID: %d\n, Grade: %f\n", student_2.name, student_2.id, student_2.grade);
+    
 
     return 0;
 }
diff --git a/src/week4_3_struct_database b/src/week4_3_struct_database
new file mode 100755
index 0000000..9da4212
Binary files /dev/null and b/src/week4_3_struct_database differ
diff --git a/src/week4_3_struct_database.c b/src/week4_3_struct_database.c
index 663b998..fd184ec 100644
--- a/src/week4_3_struct_database.c
+++ b/src/week4_3_struct_database.c
@@ -13,26 +13,61 @@
 #include <string.h>
 
 // TODO: Define struct Student with fields name, id, grade
+struct Student {
+    char name[50];
+    int id;
+    float grade;
+};
 
 int main(void) {
     int n;
     struct Student *students = NULL;
 
-    printf("Enter number of students: ");
+    printf("Write how many students you want to add: ");
+
     if (scanf("%d", &n) != 1 || n <= 0) {
-        printf("Invalid number.\n");
+
+        printf("Error: Invalid number.\n");
+
         return 1;
     }
 
     // TODO: Allocate memory for n Student structs using malloc
 
+    students = malloc( n * sizeof(struct Student) );
+
+    if (students == NULL) {
+
+        printf("Error: Memory allocation failed. \n");
+
+        return 1;
+    }
+    
     // TODO: Read student data in a loop
 
+    for (int i = 0; i < n; i++) {
+        printf("Enter data for student %d: ", i + 1);
+        // Example input format: Name ID Grade
+        scanf("%s %d %f", students[i].name, &students[i].id, &students[i].grade);
+    }
+
     // TODO: Display all student records in formatted output
 
+    printf("\n%-10s %-20s %-10s\n", "ID", "Name", "Grade");
+    for (int i = 0; i < n; i++) {
+        printf("%-10d %-20s %-6.2f\n", students[i].id, students[i].name, students[i].grade);
+    }
+    
     // Optional: Compute average grade or find top student
 
+    float total = 0;
+    for (int i = 0; i < n; i++) {
+        total += students[i].grade;
+    }
+    printf("\nAverage grade: %f\n", total / n);
+    
     // TODO: Free allocated memory
+    free(students);
 
     return 0;
 }
diff --git a/src/week5_task1_file_io b/src/week5_task1_file_io
new file mode 100755
index 0000000..db4d3eb
Binary files /dev/null and b/src/week5_task1_file_io differ
diff --git a/src/week5_task1_file_io.c b/src/week5_task1_file_io.c
index 336e21a..3f2eb57 100644
--- a/src/week5_task1_file_io.c
+++ b/src/week5_task1_file_io.c
@@ -7,21 +7,46 @@
 #include <stdlib.h>
 
 int main(void) {
-    FILE *fp;
-    char filename[100] = "data.txt";
-    char line[256];
+  FILE *fp;
+  char filename[12] = "data.txt";
+  char line[256];
+  int val_line = 0;
 
-    // TODO: 1. Open file for writing (mode = "w")
-    // TODO: 2. Check if file opened successfully
-    // TODO: 3. Write 2–3 lines of text to the file using fprintf()
-    // TODO: 4. Close the file
+  // BONUS: ask user for filename instead of using default "data.txt"
+  printf("Write down the name of the file - ");
+  scanf("%11s", filename);
 
-    // TODO: 5. Open file again for reading (mode = "r")
-    // TODO: 6. Use fgets() in a loop to read and print each line to the console
-    // TODO: 7. Close the file
+  // TODO: 1. Open file for writing (mode = "w")
+  fp = fopen(filename, "w");
+  // TODO: 2. Check if file opened successfully
+  if (fp == NULL) {
+    return 1;
+  }
+  // TODO: 3. Write 2–3 lines of text to the file using fprintf()
+  fprintf(fp, "Vote for Murad Hashimov! \n");
+  fprintf(fp, "RTU is top G \n");
+  // TODO: 4. Close the file
+  fclose(fp);
 
-    // BONUS: ask user for filename instead of using default "data.txt"
-    // BONUS: count number of lines read
+  // TODO: 5. Open file again for reading (mode = "r")
+  fp = fopen(filename, "r");
 
-    return 0;
+  if (fp == NULL) {
+    return 1;
+    ;
+  }
+
+  // TODO: 6. Use fgets() in a loop to read and print each line to the console
+  for (; fgets(line, sizeof(line), fp) != NULL; val_line++) {
+    printf("%s", line);
+  }
+
+  // BONUS: count number of lines read
+  printf("Amount of lines read - %d \n", val_line);
+
+  // TODO: 7. Close the file
+
+  fclose(fp);
+
+  return 0;
 }
diff --git a/src/week5_task2_struct_save_load b/src/week5_task2_struct_save_load
new file mode 100755
index 0000000..276e87a
Binary files /dev/null and b/src/week5_task2_struct_save_load differ
diff --git a/src/week5_task2_struct_save_load.c b/src/week5_task2_struct_save_load.c
index 267dc11..e6b759a 100644
--- a/src/week5_task2_struct_save_load.c
+++ b/src/week5_task2_struct_save_load.c
@@ -28,8 +28,11 @@ int main(void) {
     const char *filename = "student.txt";
 
     // TODO: Call save_student() to save student data to file
+    save_student(s1, filename);
     // TODO: Call load_student() to read data back into a new struct
+    Student s2 = load_student(filename);
     // TODO: Print loaded data to confirm correctness
+    printf("Name :%s , Age: %d , GPA: %.2f ", s2.name, s2.age, s2.gpa);
 
     return 0;
 }
@@ -37,13 +40,48 @@ int main(void) {
 // TODO: Implement save_student()
 // Open file for writing, check errors, write fields, then close file
 void save_student(Student s, const char *filename) {
-    // ...
+    FILE *fp = fopen(filename, "w");
+    if (fp == NULL) {
+        printf("Error opening file");
+        exit(EXIT_FAILURE);
+    }
+
+    
+    fprintf(fp, "%s\n%d\n%.2f\n", s.name, s.age, s.gpa);
+    fclose(fp);
 }
 
 // TODO: Implement load_student()
 // Open file for reading, check errors, read fields, then close file
 Student load_student(const char *filename) {
-    Student s;
-    // ...
-    return s;
+    Student stud;
+    FILE *fp = fopen(filename, "r");
+
+    if (fp == NULL) {
+        printf("Could not open file\n");
+        exit(EXIT_FAILURE);
+    }
+
+    
+    if (fgets(stud.name, MAX_NAME_LEN, fp) == NULL) {
+        fprintf(stderr, "Error name \n");
+        fclose(fp);
+        exit(EXIT_FAILURE);
+    }
+
+    
+    if (fscanf(fp, "%d", &stud.age) != 1) {
+        fprintf(stderr, "Error age \n");
+        fclose(fp);
+        exit(EXIT_FAILURE);
+    }
+
+    if (fscanf(fp, "%f", &stud.gpa) != 1) {
+        fprintf(stderr, "Error GPA \n");
+        fclose(fp);
+        exit(EXIT_FAILURE);
+    }
+    fclose(fp);
+
+    return stud;
 }
diff --git a/src/week5_task3_student_management_system b/src/week5_task3_student_management_system
new file mode 100755
index 0000000..eaa7358
Binary files /dev/null and b/src/week5_task3_student_management_system differ
diff --git a/src/week5_task3_student_management_system.c b/src/week5_task3_student_management_system.c
index 6ed6dfd..1a4e503 100644
--- a/src/week5_task3_student_management_system.c
+++ b/src/week5_task3_student_management_system.c
@@ -41,16 +41,16 @@ int main(void) {
 
         switch (choice) {
             case 1:
-                // TODO: Call list_students()
+                list_students(students, count);
                 break;
             case 2:
-                // TODO: Call add_student()
+                add_student(students, &count);
                 break;
             case 3:
-                // TODO: Call save_students() and exit loop
+                save_students(students, count);
                 break;
             default:
-                printf("Invalid option. Try again.\n");
+                printf("Error input data, try again\n");
         }
     } while (choice != 3);
 
@@ -60,24 +60,80 @@ int main(void) {
 // TODO: Implement load_students()
 // Open DATA_FILE, read records until EOF, return number of records loaded
 int load_students(Student arr[]) {
-    // ...
-    return 0;
+    int c = 0;
+    FILE *fp = fopen(DATA_FILE, "r");
+    if(fp ==NULL){
+        return 0;
+    }
+    
+    while(c<MAX_STUDENTS && fscanf(fp, "%d %s %f", &arr[c].id, arr[c].name, &arr[c].gpa)== 3){
+        c++;
+    }
+
+    fclose(fp);
+    return c;
 }
 
 // TODO: Implement save_students()
 // Write all students to DATA_FILE
 void save_students(Student arr[], int count) {
-    // ...
+    FILE *fp = fopen(DATA_FILE, "w");
+
+    if(fp==NULL){
+
+        exit(EXIT_FAILURE);
+    }
+
+    for (int i = 0; i < count; i++){
+        
+        fprintf(fp, "%d %s %f\n", arr[i].id,arr[i].name,arr[i].gpa);
+    }
+
+
+
+    fclose(fp);
 }
 
 // TODO: Implement add_student()
 // Read input from user and append to array
 void add_student(Student arr[], int *count) {
-    // ...
+    if (*count >= MAX_STUDENTS){
+        printf("Too much students");
+
+        return;
+    }
+
+    Student studs;
+
+    printf("Enter student ID: ");
+    scanf("%d", &studs.id);
+    getchar();
+
+    printf("Type student's name: ");
+    fgets(studs.name, NAME_LEN, stdin);
+
+    printf("Enter GPA: ");
+    scanf("%f", &studs.gpa);
+
+    arr[*count] = studs;
+    
+    (*count)++;
+
+    printf("students were added");
 }
 
 // TODO: Implement list_students()
 // Print all students in readable format
 void list_students(Student arr[], int count) {
-    // ...
+    if (count == 0){
+        printf("There is no students in the list\n");
+        return;
+    }
+
+    printf("\n%-7s %-10s %-3s\n", "ID", "Name", "GPA");
+
+
+    for (int i =0; i<count;i++){
+        printf("%-7d %-10s %-3.2f \n", arr[i].id, arr[i].name, arr[i].gpa);
+    }
 }