#include <bits/stdc++.h>

using namespace std;

int howManyGames(int p, int d, int m, int s) {
    // Return the number of games you can buy
    int count = 0;
    while(s >= p){
        if(p > m){
            if(s >= p){
                ++count;
                s -= p;
                p -= d;
            }
            else{
                return count;
            }        
        }
        else{
            p = m;
            if(s >= m){
                ++count;
                s -= m;
            }
            else{
                return count;
            } 
        }
    }
    return count;
}

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;
}