#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 c = p;
    int n=0;
    while(c>=m&&s>=0)
    {
        s-=c;
        if(s<0)
            break;
        else
        {
            n++;
            c-=d;
        }
    }
    while(s>=0)
    {
        s-=m;
        if(s>=0)
            n++;
    }
    return n;
}

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;
}