#include <stdio.h>

int gcd(int i, int j){
  int small, large, remainder;

  if (i <= j)
    small = i;
  else 
    small = j;

  if (i <= j)
    large = j;
  else 
    large = i;
  
  while (small > 0){
    remainder = large % small;
    large = small;
    small = remainder;
  }
  
  return large;

}


int main(void) {
  int i, j;
 
  printf("Enter two positive integers: ");
  scanf("%d %d", &i, &j);

  printf("GCD of %d and %d is %d\n\n", i, j, gcd(i,j));
  
  return 0;
}