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

namespace DanceHall
{
    class DanceHall
    {
        static void Main(string[] args)
        {
            double HallLenght = double.Parse(Console.ReadLine());
            double HallWidth = double.Parse(Console.ReadLine());
            double SquareWardrobe = double.Parse(Console.ReadLine());

            double HallArea = (HallLenght*100) * (HallWidth*100);
            double RectangleArea = HallArea / 10;
            double SquareWardrobeArea = (SquareWardrobe*100) * (SquareWardrobe*100);
            double SpaceLeftForDancers = (HallArea - RectangleArea - SquareWardrobeArea);
            double DancersCourt = SpaceLeftForDancers / 7040;

            Console.WriteLine(Math.Round(DancersCourt));
        }
    }
}