using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Lab_Methods
{
    class Program
    {
        static void Main(string[] args)
        {

            int[] number = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            int even = 0;
            int odd = 0;
            for(int i = 0; i < number.Length; i++)
            {

                if(number[i] % 2 == 0)
                {
                    even = even + number[i];
                }
                else
                {
                    odd = odd + number[i];
                }
            }
            Console.WriteLine(even * odd);
        }

    }
}