#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define mp make_pair
#define F first
#define S second
#define D double
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define INP freopen("in","r",stdin);


int main(){
	ll p,d,m,s;
	cin>>p>>d>>m>>s;
	ll ans =0;

	while(s>=0){
		if(p >=m){			
			if(s-p >=0){
				s-=p;
				ans++;
			}else break;
			p-=d;
		}else{
			if(s>=m){
				ans++;
				s-=m;				
			}else break;
		}
	}	
	cout<<ans<<endl;
}