#include<bits/stdc++.h>
using namespace std;
int p,d,m,s,ans=0;
int main()
{
    cin>>p>>d>>m>>s;
    while(true)
    {
        int dam=max(p,m);
        p-=d;
        s-=dam;
        if(s>=0)
        ans++;
        else
        break;
    }
    cout<<ans<<endl;
    return 0;
}