import java.io.*; import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*; public class Solution { static int howManyGames(int p, int d, int m, int s) { int currentMoney = s; int currentCost = p; int games = 0; while (currentCost <= currentMoney) { currentMoney -= currentCost; if (currentCost - d >= m) { currentCost -= d; } else { currentCost = m; } games++; } return games; } public static void main(String[] args) { Scanner in = new Scanner(System.in); int p = in.nextInt(); int d = in.nextInt(); int m = in.nextInt(); int s = in.nextInt(); int answer = howManyGames(p, d, m, s); System.out.println(answer); in.close(); } }