Problem:
Greatest Common Divisor

Write a program which finds the greatest common divisor of two natural numbers a and b

Input

a and b are given in a line sparated by a single space.

Output

Output the greatest common divisor of a and b.

Constrants

1 ≤ a, b ≤ 109

Hint

You can use the following observation:

For integers x and y, if x ≥ y, then gcd(x, y) = gcd(y, x%y)

Sample Input 1

54 20

Sample Output 1

2

Sample Input 2

147 105

Sample Output 2

21

Solution in C (judge verdict: Time Limit Exceeded)

#include <stdio.h>

int main(void)
{
  int x,y;
  int d=1;
  int i;
  int big;
  
  scanf("%d%d",&x,&y);

  if(x > y){
    big = x;
  }else{
    big = y;
  }

  for(i=2; i<=big; i++){
    if(((x%i) == 0) && ((y%i) == 0 )){
      d = i;
    }
  }

  printf("%d\n",d);
  

  return(0);
}