#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
    int p,d,m,s;
    cin >> p >> d >> m >> s;
    int sum = 0;
    int item = 1 ;
    while ( sum <= s)
    {
    sum = sum + p;
    if(p > m)
    {
    p--;
    }
    item ++;
    }
    cout << item ;
}