using System;

class Math

{

    protected int num1;

    protected int num2;

    public void input(int x, int y)

    {

        num1 = x;

        num2 = y;

    }

}

class Sum : Math

{

    public void Add()

    {

        Console.WriteLine(num1 + " + " + num2 + " = " + (num1 + num2));

    }

}

public class Program

{

    public static void Main()

    {

        Sum group1 = new Sum();

        group1.input(5, 10);

        group1.Add();

    }

}