#include <iostream>
#include<bits/stdc++.h>
using namespace std;
 
int main() {
	// your code goes here
	int n ; cin>>n;
	vector<int>arr(n);
	for(int i = 0 ; i<n;i++){
		cin>>arr[i];
	}
	sort(arr.begin(),arr.end(),greater<int>());
	int k ; cin>>k;
	int p ; //pair_wise sum 
	cin>>p;
	int i = 0 ; int t_cost = 0 ; 
	while(i<2*k && i<n && (arr[i]+arr[i+1])>p){
	   t_cost+=p;
	   i=i+2;
	}
	while(i<n){
		t_cost+=arr[i];
		i++;
	}
	cout<<t_cost;
 
	return 0;
}

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NSAKOSAxMSAxMyAxNSAxNyAKMiAKNg==

5 
9 11 13 15 17 
2 
6