using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("ENTER NUMBER :");

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

        double x ;

        if (num<0)

            x = (num*num);

        else

            x=Math.Sqrt(num);

        Console.WriteLine("the result is : " + x );

    }

}