#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

int main() {
  int a, b, c, d;
  cin >> a >> b >> c >> d;
  int ans = 0;
  for (int i = 0; i <= a; i++) {
    if (i * c <= b && i + i * c <= d) {
      ans = i;
    }
  }
  cout << ans << '\n';
}