#include <bits/stdc++.h>

using namespace std;

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