#include <bits/stdc++.h>

using namespace std;

int howManyGames(int p, int d, int m, int s) {
    
    int count = 0, sum = 0, i=0;
    
    while(sum <= s){
        if((p-i*d) >= m){
            sum = sum + (p-i*d);
            i++;
            count++;
        }else{
            sum = sum + m;
            count++;
        }
        
    }
    return count-1;
    
}

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;
}