Program to add two integers using function

 #include <stdio.h>

/* User defined function sum that has two int
 * parameters. The function adds these numbers and
 * return the result of addition.
 */
int sum(int a, int b){
   return a+b;
}
int main()
{
   int num1, num2, num3;
   printf("Enter first number: ");
   scanf("%d", &num1);
   printf("Enter second number: ");
   scanf("%d", &num2);

   //Calling the function
   num3 = sum(num1, num2);
   printf("Sum of the entered numbers: %d", num3);
   return 0;
}

Output:

Enter first number: 22
Enter second number: 7
Sum of the entered numbers: 29