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 JAVA (judge verdict: Wrong Answer)


import java.io.*;
import java.util.*;

class Main{
	public static void main(String[] args){
		solve();
	}

	public static void solve(){
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = sc.nextInt();
		if(x<y){
			int tmp = x;
			x = y;
			y = x;
		}

		while(true){
			int a = x % y;
			if(a==0){
				break;
			}
			x = y;
			y = a;
		}

		System.out.println(y);
	}
}