大数模板Java

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