using System;

public class Program

{

    public static void Main()

    {

        start:

        Console.WriteLine("Please enter a number.");

        long x = long.Parse(Console.ReadLine());

        if (x >= -9223372036854775808 && x <= 9223372036854775807)

        {

        if(x>0)

            Console.WriteLine("Your number is positive.");

        else if (x <0)

            Console.WriteLine("Your number is negative.");

        else Console.WriteLine("You entered 0!");

        }

        else if (x < -9223372036854775808 && x > 9223372036854775807)

        {

            Console.WriteLine("ERROR. Please enter a valid number");

            goto start;

        }

    }

}