7-1 接口--四则计算器 (10 分)利用接口做参数，写个计算器，能完成加减乘除运算。定义一个接口ICompute含有一个方法int computer(int n, int m)。定义Add类实

import java.util.Scanner;
interface ICompute{
    public int computer(int n, int m);
}
class Add implements ICompute{
    public int computer(int n, int m){
        return n + m;
    }
}

class Sub implements ICompute{
    public int computer(int n, int m){
        return n - m;
    }
}

public  class Main{
    public static void main(String[] args) {
		Add a = new Add();
		Sub s = new Sub();
		Scanner scan = new Scanner(System.in);
		int number1 = scan.nextInt();
		int number2 = scan.nextInt();
		System.out.println(a.computer(number1,number2));
        System.out.println(s.computer(number1,number2));
	}
}