#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
template <typename T>
string ts(T v) {
  string res = "{";
  bool r = true;
  for (const auto &x : v) {
    if (!r) res += ",";
    r = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
bool comp(pair<ll, ll> a, pair<ll, ll> b) {
  return (a.first < b.first && a.second > b.second);
}
void solve() {
  ll n;
  cin >> n;
  ll arr[n];
  for (int i = 0; i < int(n); i++) cin >> arr[i];
  ll ans = 0;
  ll f, x;
  cin >> f >> x;
  for (int i = 0; i < int(n); i++) {
    ans += ceil((double)(arr[i] - f) / (f + x));
  }
  cout << ans * x << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) solve();
}
