利用java 快速實現加減乘數餘運算

import java.util.Scanner;
import java.math.*;
public class Main {
	public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	String s1 = sc.next();
	String s2 = sc.next();
	BigInteger a2 = new BigInteger(s1);
    BigInteger b2 = new BigInteger(s2);
    
    BigInteger result1=a2.add(b2);  //加法
    BigInteger result2 = a2.mod(b2);  //a2 mod b2取餘
    BigInteger result3 = a2.multiply(b2);  //乘法
    BigInteger result4 = a2.divide(b2);    //除法 a2/b2 b2 = 0.會終止程序，拋出異常
    BigInteger result5 = a2.subtract(b2);  //減法。a2 - b2.+
    
    System.out.println (result1 );
    System.out.println (result2 );
    System.out.println (result3 );
    System.out.println (result4 );
    System.out.println (result5 );

}
}