#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int a, b, pm;
  int sum;
  cin >> n >> a >> b >> pm;
  sum = pm;
  int top[100];
  for (int i = 0; i < n; i++) {
    int k;
    cin >> k;
    top[i] = k;
  }
  sort(top, top + n);
  reverse(top, top + n);
  for (int i = 0; i < b; i++) {
    sum += top[i];
  }
  cout << sum / (a + b * b) << endl;
  return (0);
}
