namespace Problem_12.Number_checker
{
    using System;
 
    public class Program
    {
        public static void Main()
        {
            var input = Console.ReadLine();
 
            int numberStorage;
            if(Int32.TryParse(input, out numberStorage))
            {
                Console.WriteLine("It is a number.");
            }
 
            else
            {
                Console.WriteLine("Invalid input!");
            }
        }
    }
}

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