#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 cost=p+d;
    int count=0;
    while(1)
    {
        if(cost-d>=m)
        {
            cost=cost-d;
        }
        else
        {
            cost=m;
        }
        if(s-cost>=0)
        {
            s=s-cost;    
            count++;
        }
        else
            break;
        
        
        
    }
    return (count);
}

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;
}