using System;

using System.Collections.Generic;   

​

public class Program

{

    public static class SquareRootPrecalcurator

    {

     public const int MaxValue = 1000;

    private static List<double> sqrtValues;

    static SquareRootPrecalcurator()

    {

     sqrtValues = new List<double>();

    for (int i = 0 ; i <= MaxValue ; i++)

        sqrtValues.Add( Math.Sqrt(i));

    }

        public static double GetSqrt( int value)

        {

         return sqrtValues[ value ] ;

        }

    }

    public static void Main()

    {

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

        Console.WriteLine("{0}" , SquareRootPrecalcurator.GetSqrt(number));

    }

}