#include <bits/stdc++.h>

using namespace std;

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

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;
}