#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int m,p,d,s;
    cin>>p>>d>>m>>s;
    int i =0;
    while(s>=0)
    {
        s-= max(m,p);
        if(s>=0)
            i++;
        p-=d;
       
    }
    cout<<i<<endl;
    return 0;
}