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: Runtime Error)

import java.util.Scanner;


public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x=sc.nextInt();
		int y=sc.nextInt();
		if(x>=y){
			System.out.println(solve(x,y));
		}else{
			System.out.println(solve(y,x));
		}
	}

	static int solve(int x,int y){//x>y
		int a=x%y;
		return gcd(x,a);


	}
	static int gcd(int x,int y){
		int r=0;
		while(x%y!=0){
			r=x%y;
			x=y;
			y=r;
		}
		return y;
	}

	}