#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 ans;
    int n;
    if(s < p){
        ans = 0;
    }
    if(s >= p && s < 2*p-d){
        ans = 1;
    }
    n = (p-m)/d;
    for(int i=3; i<=n; i++){
        if(s >= (i-1)*p-(i-2)*d && s < i*p-(i-1)*d){
            ans = i;
            return ans;
        }
    }
    ans = m;

    s = s-n*p-(n-1)*d;
    while(s > 0)
    {
        ans += 1;
        s=s-m;
        cout << s;
    }
    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;
}