using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution
{

    static int HowManyGames(int startPrize, int cheaper, int minPrize, int money)
    {
        var bought = 0;
        var stillCanBuy = true;
        if(money >= startPrize)
        {
            bought++;
            money -= startPrize;
        }
        else
        {
            stillCanBuy = false;
        }

        while(stillCanBuy)
        {
            if(startPrize - cheaper > minPrize)
            {
                startPrize -= cheaper;
                if(startPrize <= money)
                {
                    bought++;
                    money -= startPrize;
                }
                else
                {
                    stillCanBuy = false;
                }
            }
            else
            {
                startPrize = minPrize;
                if (startPrize <= money)
                {
                    bought++;
                    money -= startPrize;
                }
                else
                {
                    stillCanBuy = false;
                }
            }
        }

        return bought;
    }

    static void Main()
    {
        string[] tokens_p = Console.ReadLine().Split(' ');
        int p = Convert.ToInt32(tokens_p[0]);
        int d = Convert.ToInt32(tokens_p[1]);
        int m = Convert.ToInt32(tokens_p[2]);
        int s = Convert.ToInt32(tokens_p[3]);
        int answer = HowManyGames(p, d, m, s);
        Console.WriteLine(answer);
        Console.ReadLine();
    }
}