10. Invalid Number

using System;

namespace InvalidNumber
{
    class Program
    {
        static void Main(string[] args)
        {
            int num = int.Parse(Console.ReadLine());

            if (num >=100 && num <=200 || num == 0)
            {
                Console.WriteLine();
            }
            else
            {
                Console.WriteLine("invalid");
            }
        }
    }
}