using System;

public class Program

{

    public static void Main(string[] args)

    {

        Console.WriteLine("Awaiting for x to be pasted...");

        Console.Write("x=");

        string input = Console.ReadLine();

        double x = double.Parse(input);

        double y = 0;

        if (x <= -7 || x >= 4) 

        {

            y = 0;

        } 

        else if (x >= -7 && x <= -3)

        {

            y = (x + 7);

        }

        else if (x >= -3 && x <= -2) 

        {

            y = 4;

        }

        else if (x >= -2 && x <= 2) 

        {

            y = x * x;

        }

        else if (x >= 2 && x <= 4)

        {

            y = 8 - 2 * x;

        }

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

    }

}