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(){
  int x,y,x1,y1,i,j,ans;

  scanf("%d %d",&x,&y);

    for(i=1;i<=y;i++){
      
      if(y%i==0){
	y1=i;
      
      for(j=1;j<=x;j++){
        if(x%j==0) {
	  x1=j;
	if(x1==y1) ans=j;
	}
      }
      }
    }
  

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