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

int main()
{
   int p,d,m,s;
   cin>>p>>d>>m>>s;
   int count=0;
   for(int i=0;s>0;i++)
   if(p-i*d>m)
   {if(s>=p-i*d){count++;s-=p-i*d;}
    else
    break;}
   else
   {if(s>=m){count++;s-=m;}else break;}
   cout<<count<<endl;
}