#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;
    int p1=p;
    while(s>=0 && s>=m && p>=m)
    {
        p1=p-d;
       // cout<<"p1 = "<<p1<<endl;
        p=p1;
        s=s-p1;
       // cout<<"s = "<<s<<endl;
        count++;
        //cout<<"count = "<<count<<endl;
    }
    return count+1;
    
    
}

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;
}