#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = (l); i < (r); i++)
using namespace std;

typedef long long ll;

int main() {
    int N, A, B, X, Y;
    cin >> N >> A >> B >> X >> Y;
    vector<int> H(N);
    rep(i, 0, N) cin >> H[i];
    int ok = 1e9, ng = -1;
    while (ok > ng + 1) {
        int md = (ok + ng) / 2;
        priority_queue<int> pq;
        rep(i, 0, N) {
            pq.push(max(0, H[i] - md));
        }
        rep(i, 0, A) {
            int p = pq.top();
            pq.pop();
            pq.push(max(0, p - X));
        }
        ll S = 0;
        while (!pq.empty()) {
            int p = pq.top();
            pq.pop();
            S += p;
            //cout << "p=" << p << endl;
        }
        if (1LL * Y * B >= S) ok = md;
        else ng = md;
    }
    cout << ok << endl;
}