using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace sx8_1
{
    interface Ijia
    { void jia();}

    interface Ijian
    { void jian();}

    class jisuan : Ijia, Ijian
    {
        public int a;
        public int b;

        public jisuan(int A, int B)
        { a = A; b = B; }
        public void jia()
        { return a + b; }

    }

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入第一个数：");
            int m = int.Parse(Console.ReadLine());

            Console.WriteLine("请输入第二个数：");
            int n = int.Parse(Console.ReadLine());

            ji suan js = new jia(m, n);
            Console.ReadLine("两数之和是：{0}", jia());
            jisuan js = new jian(m, n);

            
                Console.ReadLine("两数之差是：{0}", jia());
                Console.ReadLine();
            
        }



    }
}

看来这个太  不好搞了  哎……自己琢磨吧！这C#基础有啥难的？老子得搞定他哎…………

太感谢了，真是帮了大忙了！