using System;

public class Program

{

    public static double func2(int x)

    {  double f1;

       f1=(2*Math.Pow(x,1/3))/2*x+1;

       return f1;

    }

    public static void Main()

    { int n= Convert.ToInt32(Console.ReadLine());

     double y= func2(n);

     Console.WriteLine("y="+y);

    }

}