#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main(){
  ll N,A,B,X,Y;
  cin>>N>>A>>B>>X>>Y;
  vector<ll> H(N);
  for(int i=0;i<N;i++){
    cin>>H[i];
  }
  ll L=0;
  ll R=1000000000;
  ll M,x;
  while(L<R){
    M=(L+R)>>1;
    priority_queue<ll> que;
    for(int i=0;i<N;i++){
      que.push(max(0LL,H[i]-M));
    }
    for(int i=0;i<A;i++){
      x=que.top();
      que.pop();
      x=max(0LL,x-X);
      que.push(x);
    }
    x=0;
    while(!que.empty()){
      x+=que.top();
      que.pop();
    }
    if(x<=B*Y){
      R=M;
    }else{
      L=max(L+1,M);
    }
  }
  cout<<L<<"\n";
}