#include <stdio.h>

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

  small = i <= j ? i : j;
  large = i <= j ? j : i;
  
  while (small > 0){
    remainder = large % small;
    large = small;
    small = remainder;
  }

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