#include <stdio.h>

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

  a = i; b = j;
  
  while (a != b)
     if (a > b)
        a -= b;
     else
        b -= a;   

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