大数 gcd

转自：https://blog.csdn.net/weixin_43914593/article/details/107508909?utm_source=app

import java.math.*;
import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        BigInteger a = in.nextBigInteger();
        BigInteger b = in.nextBigInteger();
        System.out.println(a.gcd(b));
    }
}