#include <bits/stdc++.h>
using namespace std;
using lint = long long;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;

int main() {
  cin.tie(nullptr); ios::sync_with_stdio(false);
  int a, b, c, d; cin >> a >> b >> c >> d;
  int res;
  for (int x = 0; ; ++x) {
    if (x > a) break;
    if (c * x > b) break;
    if (x + c * x > d) break;
    res = x;
  }
  cout << res << '\n';
}