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, i, temp;
    int d = 0;
    
    scanf("%d %d", &x, &y);
    
    if (x < y){
        temp = x;
        x = y;
        y = temp;
    }
        
    for(i = y; i >= 1; i--){
        if(y % i == 0){
            if(x % i == 0){
                d = i;
                break;
            }
        }
    }
    printf("%d\n", d);
}