#include <stdio.h>

int add(int a, int b)
{
  return a + b;
}

int mul(int a, int b)
{
  return a * b;
}

int main()
{
  int result;

  result = add(10, 20);
  printf("add result is %d\n", result);
  result = mul(10,20);
  printf("multiply result is %d\n", result);

  return 0;
}