using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
using System.Text.RegularExpressions;
using System.Linq;

public class Program
{
    public static void Main(string[] args)
    {
        new Magatro().Solve();
    }
}

class Magatro
{
    private int H, A, D;
    public void Solve()
    {
        string[] line = Console.ReadLine().Split(' ');
        H = int.Parse(line[0]);
        A = int.Parse(line[1]);
        D = int.Parse(line[2]);

        double min = 999999;

        for (int i = 0; i <= (H - 1 + A) / A; i++)
        {
            int n = Math.Max(0, H - A * i);
            int c = (n - 1 + D) / D;
            min = Math.Min(min, 1.5 * c + i);
        }

        Console.WriteLine(min);
    }
}