using System;

public class Program

{

    public static void Main()

    {

        float dmayor, dmenor, area;

        Console.WriteLine("AREA DEL ROMBO");

        Console.WriteLine("INGRESA LA DIAGONAL MAYOR");

        dmayor = float.Parse(Console.ReadLine());

        Console.WriteLine("INGRESA LA DIAGONAL MENOR");

        dmenor = float.Parse(Console.ReadLine());

        area = (dmayor * dmenor) / 2;

        Console.WriteLine("EL AREA ES: " + area);

    }

}