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()
{

    long long int i, a,b;

    scanf("%lld %lld", &a, &b);



    long long int max=0;

    for(i=1; i<=a && i<=b; i++)
    {
        if(a%i==0 && b%i==0)
        {
            if(i>max)
                max=i;
        }
    }
    printf("%lld\n", max);


    return 0;
}