using System;

public class Program

{

    public static void Main()

    {

        double n_1 ,n_2, n_3, S, M;

        n_1=double.Parse(Console.ReadLine());

        n_2=double.Parse(Console.ReadLine());

        n_3=double.Parse(Console.ReadLine());

        S= (n_1*n_2)/2;

        M= n_1+n_2+n_3;

        Console.WriteLine("the S={0} and the M={1}",S,M); 

    }

}