#include <bits/stdc++.h>
using namespace std;
typedef long long int lld;

#define dbg(x) cerr << #x << " = " << x << endl
#define dbg2(x,y) cerr<<#x<<"="<<x<<" "<<#y<<"="<<y<< endl

void solve()
{
	int s,m,d,p;
	cin>>p>>d>>m>>s;

	int ans=0;

	while(s>0)
    {
        if(s-p>=0 and p>m)
        {
            ans+=1;
            s-=p;
            p-=d;
        }
        else if(p<=m and s-m>=0)
        {
              ans+=1;
                s-=m;
           
        }
        else break;
    }
	cout<<ans<<endl;

}


int main()
{
	int t;
	//cin>>t;
	t=1;
	
	while(t--)
	{
		solve();
	}
	return 0;
}