Dance Hall

using System;

namespace Dance_Hall
{
    class Program
    {
        static void Main(string[] args)
        {
            double l = double.Parse(Console.ReadLine());
            double w = double.Parse(Console.ReadLine());
            double a = double.Parse(Console.ReadLine());
            double hall = (l * 100) * (w * 100);
            double wardrobe = (a * 100) * (a * 100);
            double bench = hall / 10;
            double freespace = hall - wardrobe - bench;
            double dancers = freespace / (40 + 7000);
            Console.WriteLine(Math.Floor(dancers));
        }
    }
}