#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 p,d,m,s;
    cin>>p>>d>>m>>s;
    int i,x=0;
    while(p>0)
    {
        if(p-d>m){
            x=x+p;
            p=p-d;}
        else{
            x=x+p;
            p=m;
            
        }
        if(x<=s)
        i++;
        else
            break;
    }
    cout<<i;
    return 0;
}