大数乘法java版

import java.util.*;
import java.math.*;

public class NumMul{
    public static void main(String args[]){
        Scanner cin = new Scanner(System.in);
        BigInteger a, b;
        while(cin.hasNext()){
            a = cin.nextBigInteger();
            b = cin.nextBigInteger();
            System.out.println(a.multiply(b));
        }
    }
}