using System;

namespace Ex

{

    public class Program

    {

        public static void Main (string[] args)

        {

        int num;

        Console.WriteLine("enter a tav number:");

        num=int.Parse(Console.ReadLine());

        if (num>=10)

        {

            if (num<=90)

            {

                Console.WriteLine("2 digit number");

            }

            else

            {

                Console.WriteLine("3 or more digit number");

            }

        }

        else

        }

        Console.WriteLine("1 digit number");

        }

    }

    }}

​

​