#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

ll N, A, B, X, Y;
vector<ll> H;

bool solve(ll c){

    ll S=0, h, a=A;
    priority_queue<ll> que;
    for (int i=0; i<N; i++){
        if (H[i]-c > 0) que.push(H[i]-c);
    }

    while(!que.empty() && a){
        h = que.top();
        que.pop();
        h -= X;
        a--;
        if (h > 0) que.push(h);
    }

    while(!que.empty()){
        h = que.top();
        S += h;
        que.pop();
    }

    return S <= B*Y;
}

int main(){

    cin >> N >> A >> B >> X >> Y;
    H.resize(N);
    for (int i=0; i<N; i++) cin >> H[i];

    ll l=-1, r=1e9, c;
    while(r-l>1){
        c = (l+r)/2;
        if (solve(c)) r=c;
        else l=c;
    }

    cout << r << endl;
}