using System;

public class Program

{

    public static void Main()

    {

     //vhod

double stena12 = 10;

double stenavrata= 6.5;

double vrata = 1.8;

double tavan = 12;

double visochina = 2.5;

double staqplochki = stena12 * 2 + (stenavrata - vrata) + stenavrata + tavan;

Console.WriteLine(staqplochki);

    }

}