#include <bits/stdc++.h>

using namespace std;

int howManyGames(int p, int d, int m, int s) {
    int ans = 0;
    int val;
	int temp = 0;
	while(true)
	{
		val = p-temp;
		val = max(val, m);
		if(val<=s)
		{
			ans++;
			s-=val;
		}
		else
			break;
		temp += d;
	}
    return ans;
}

int main() {
    int p;
    int d;
    int m;
    int s;
    cin >> p >> d >> m >> s;
    int answer = howManyGames(p, d, m, s);
    cout << answer << endl;
    return 0;
}