using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Enter number");

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

        double num1 = Math.Pow(x,2);

        double num2 = Math.Sqrt(x);

        if(x<0)

            Console.Write(num1);

        else

            Console.WriteLine(num2);

    }

}