// Program to find the greatest number, middle number or check if a number is positive, negative or zero.

​

using System;

public class Program

{

    public static void Main()

    {   

        Console.WriteLine("Do you want to find the greatest number, middle number or check if a number is positive, negative or zero. Press A,B,C for respective choices:");

        string userInput = Console.ReadLine().ToUpper();

        if (userInput == "A")

        {

            firstOption();

        }

        else if (userInput == "B")

        {

            secondOption();

        }

        else

        {

            thirdOption();

        }

    }

    public static void firstOption()

    {

        int num01;

        int num02;

        int num03;

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

        num01 = Convert.ToInt32(Console.ReadLine());

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

        num02 = Convert.ToInt32(Console.ReadLine());

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

        num03 = Convert.ToInt32(Console.ReadLine());

        if (num01 > num02 && num01 > num03)

        {

            Console.WriteLine(num01 + " is the largest number.");

        }

        else if (num02>num01 && num02> num03)

        {

            Console.WriteLine(num02 + " is the greatest number.");

        }

        else 

        {

            Console.WriteLine(num03 + " is the greatest number");

        }

    }

​

    public static void secondOption()

    {

        int num01;

        int num02;

        int num03;

        Console.WriteLine("Enter a number");

        num01 = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("Enter a number");

        num02 = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("Enter a number");

        num03 = Convert.ToInt32(Console.ReadLine());

        if (num01 > num02 && num01 < num03 || num01 < num02 && num01 > num03 ) 

        {

            Console.WriteLine(num01 + " is the middle number.");

        }

        else if (num02 > num01 && num02 < num03 || num02 < num01 && num02 > num03)

        {

            Console.WriteLine(num02 + " is the middle number.");

        }

        else

        {

            Console.WriteLine(num03 + " is the middle number.");

        }

    }

    public static void thirdOption()

    {

        int num01;

        Console.WriteLine("Enter a number");

        num01 = Convert.ToInt32(Console.ReadLine());

        if (num01 > 0 )

        {

            Console.WriteLine(num01 + " is a positive number.");

        }

        else if (num01 < 0) 

        {

            Console.WriteLine(num01 + " is a negative number.");

        }   

        else

        {

            Console.WriteLine(num01 + " is a zero.");

        }

    }

​

}