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 n1,n2,i,gcd;
    scanf("%d %d",&n1,&n2);

    for(i=1;i<=n1 && i<=n2;i++)
    {
           if(n1%i==0 && n2%i==0){
            gcd=i;

    }
    }

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

    return 0;
}