помогите победить валидатор:)
package com.javarush.task.task14.task1420;
/*
НОД
*/
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
int num1 = Integer.parseInt(reader.readLine());
int num2 = Integer.parseInt(reader.readLine());
while (num1 != 0 && num2 != 0) {
if (num1 > num2) num1 = num1 % num2;
else num2 = num2 % num1;
}
System.out.println(num1 + num2);
}
}