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,d,ans=0;
        scanf("%d %d",&x,&y);
if(x<y){
d=x;
x=y;
y=d;}
 
        for(d=1;d<=x;d++){
            if(x%d==0&&y%d==0){ans=d;}
            }
 printf("%d\n",ans);        
               return 0;}