using System;
class Math
{
protected int num1 , num2;
public void input (int x , int y)
num1 = x;
num2 = y;
}
class Sum : Math
public void Add()
Console.WriteLine("The sum of " + num1 + " and " + num2 + " is " + (num1 + num2));
public class Program
public static void Main()
Sum group1 = new Sum();
group1.input(5,10);
group1.Add();