#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 cnt=0,i,j,rs,temp;
    for(i=0;i<10000;i++)
    {
        temp=p-(i*d);
        if(temp>=m)
        {rs+=temp;cnt++;}
        else
        {
            temp=m;
            rs+=temp;cnt++;
        }
        if(rs>s)
        {cnt--;break;}
        
    }
    return cnt;
}

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;
}