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

namespace kjsg
{
    class Program
    {
        static void Main(string[] args)
        {
            var savedMoney = decimal.Parse(Console.ReadLine());
            var widthFloor = decimal.Parse(Console.ReadLine());
            var lenghtFloor = decimal.Parse(Console.ReadLine());
            var heightTriangle = decimal.Parse(Console.ReadLine());
            var sideTriangle = decimal.Parse(Console.ReadLine());
            var pricePerTile = decimal.Parse(Console.ReadLine());
            var priceMaster = decimal.Parse(Console.ReadLine());

            var areaFloor = widthFloor * lenghtFloor;
            var areaTile = heightTriangle * sideTriangle/2;
            var neededTiles = Math.Ceiling(areaFloor / areaTile) + 5;
            var priceForTiles = neededTiles * pricePerTile;
            var totalSpend = priceForTiles + priceMaster;
            var result = Math.Abs(savedMoney - totalSpend);
            if (savedMoney >= totalSpend) Console.WriteLine($"{result:F2} lv left.");
            else Console.WriteLine($"You'll need {result:F2} lv more.");
        }
    }
}