#include <bits/stdc++.h>

using namespace std;

#define rep(i, n) for (int i = 0; i < (int)n; ++i)
#define FOR(i, a, b) for (int i = a; i < (int)b; ++i)
#define rrep(i, n) for (int i = ((int)n - 1); i >= 0; --i)

using ll = long long;
using ld = long double;

__attribute__((unused)) const ll INF = 1e18;
__attribute__((unused)) const int Inf = 1e9;
__attribute__((unused)) const double EPS = 1e-9;
__attribute__((unused)) const ll MOD = 1000000007;

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(0);
  int n;
  ll a, b, x, y;
  cin >> n >> a >> b >> x >> y;
  vector<ll> h(n);
  rep(i, n) { cin >> h[i]; }
  sort(h.begin(), h.end());
  ll left = 0LL, right = INF, mid;
  while (right - left > 1) {
    mid = (left + right) / 2;
    priority_queue<ll> pq;
    rep(i, n) {
      ll tmp = h[i] - mid;
      if (tmp <= 0) continue;
      pq.push(tmp);
    }
    rep(i, a) {
      if (pq.size() == 0) break;
      ll t = pq.top();
      pq.pop();
      t -= x;
      if (t <= 0) continue;
      pq.push(t);
    }
    ll lim = y * b;
    while (!pq.empty()) {
      ll t = pq.top();
      pq.pop();
      lim -= t;
    }
    if (lim >= 0)
      right = mid;
    else
      left = mid;
  }
  cout << right << endl;

  return 0;
}