#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
const int mod = 1000000007;
const long long INF = 1LL << 60;
using ll = long long;

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

bool solve(ll K){
  
  auto h=H;
  rep(i,N){
    h[i]-=K;
  }

  priority_queue<pair<ll,ll>> que;
  rep(i,N){
    que.push(make_pair(h[i],i));
  }

  rep(iter,A){
    auto Q=que.top();
    ll maxh=Q.first;
    ll i=Q.second;
    que.pop();

    h[i]-=X;
    if(h[i]<0) h[i]=0;
    que.push(make_pair(h[i],i));
  }

  ll sum=0;
  rep(i,N){
    if(h[i]>0) sum+=h[i];
  }

  return sum>=B*Y;
}

int main()
{
  
  cin >> N >> A >> B >> X >> Y;
  H.resize(N);
  rep(i,N){
    cin >> H[i];
  }

  ll OK=0;
  ll NG=10010010010;

  while(abs(OK-NG)>1){
    ll mid=(OK+NG)/2;
    if(solve(mid)){
      OK=mid;
    }
    else{
      NG=mid;
    }
  }
  
  cout << OK+1 << endl;
}