using System;               

public class Pentagono

{

    public int apotema;

    public int perimetro;

    public void Area()

    {

        Console.WriteLine(perimetro*apotema/2);

    }

}

    public class Programa

{

       public void Main()

{

Pentagono pentagonopeque =new Pentagono();

Console.WriteLine("perimetro");

pentagonopeque.perimetro=Convert.ToInt32(Console.ReadLine());

Console.WriteLine("apotema");

pentagonopeque.apotema=Convert.ToInt32(Console.ReadLine());

Console.WriteLine("Area");

pentagonopeque.Area();

}

}