#include <bits/stdc++.h>

using namespace std;

int howManyGames(int p, int d, int m, int s) {
    int ans;
    if((p<=m)&&(s-m>=0)){
        ans = 1 + howManyGames(m,d,m,s-m);
    }
    else if ((p>m)&&(s-p>=0)){
        ans = 1 + howManyGames(p-d,d,m,s-p);
    }
    else{
        ans = 0;
    }
    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;
}