#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  Int a,b,c,d;
  cin>>a>>b>>c>>d;
  Int x=0;
  while(1){
    Int y=x+1;
    if(y>a) break;
    if(y*c>b) break;
    if(y+y*c>d) break;
    x++;
  }
  cout<<x<<endl;
  return 0;
}