#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int ar[n];
  for (int i = 0; i < n; i++) cin >> ar[i];
  int f, x;
  cin >> f >> x;
  long long res = 0;
  for (int i = 0; i < n; i++) {
    if (ar[i] > f) {
      int t = ar[i] - f;
      res += ((t / (f + x)) + (t % (f + x) != 0)) * x;
    }
  }
  cout << res << endl;
}
