using System;

public class Program

{

    public static void Main()

    {double A;

     double B;

     double P;

     double Deh;

    A=double.Parse(Console.ReadLine());

    B=double.Parse(Console.ReadLine());

     P=A*B ;

     Deh=P/2;

     Console.WriteLine("the P is:{0}",P);

      Console.WriteLine("the Deh is:{0}",Deh);

    }

}