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));
         }
     }
 }