#include <bits/stdc++.h>

using namespace std;

long long int howManyGames(long long int p,long long  int d,long long  int m,long long  int s) {
    long long int nbuy = 0;
    while(s>0){
        if(nbuy==0){
            if((s-p) >= 0){
                s = s-p;
                nbuy++;
            }else return nbuy;
        }
        else{
            if((p-d)>m){
                if((s-p+d) >= 0){                    
                    p -= d;
                    s = s-p;
                    nbuy++;
                }else return nbuy;
            }
            else{
                 if((s-m) >= 0){
                    s = s-m;
                    nbuy++;
                 }
                else return nbuy;
            }
       }
    }
    
    return nbuy;
}

int main() {
    long long int p;
    long long int d;
    long long int m;
    long long int s;
    cin >> p >> d >> m >> s;
    long long int answer = howManyGames(p, d, m, s);
    cout << answer << endl;
    return 0;
}