using System;

​

class Math

{

    public int num1;

    public int num2;

    public int diff;

    public Math(int x,int y)

    {

        num1=x;

        num2=y;

    }

    public int minus()

    {

        return(num1-num2);

    }

    public void Minus()

    {

        Console.WriteLine("The difference are " +(num1-num2));

    }

}

public class Program

{

    public static void Main()

    {       

        Console.WriteLine("Enter first number");

        int num1 = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("Enter second number:");

        int num2 = Convert.ToInt32(Console.ReadLine());

        while(num1 < num2)

        {

            Console.WriteLine("first number must be larger than " + num2 +". Enter again: ");

            num1 = Convert.ToInt32(Console.ReadLine());

        }

        Math Group1=new Math(num1,num2);

        Group1.Minus();

    }

}