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

#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define pb push_back
#define x first
#define y second
#define FOR(i, a, b) for(ll i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)

typedef long long ll;
typedef double db;
typedef long double LD;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<db, db> pdd;

const ll INF = 1e13;

int solve()
{
	ll n,k,lc,pc,lm,pm,t,d;
	if (!(cin >> n>>k))
		return 1;
	cin >> lc >> pc >> lm >> pm >> t >> d;
	vector<ll> ar(n);
	FOR(i,0,n)
		cin >> ar[i];
	sort(rall(ar));
	vector<ll> p1(n+1);
	FOR(i,0,n)
		p1[i+1] = max(ar[i]-lc,0ll);
	FOR(i,1,n+1)
		p1[i] += p1[i-1];
	auto getSum1 = [&](ll l, ll r) -> ll
	{
		return p1[r + 1] - p1[l];
	};
	vector<ll> p2(n+4);
	FOR(i,0,n){
		p2[i+1] = min(ar[i]-lc,0ll);
		if(p2[i+1] < -d)
			p2[i+1] = -INF;
	}
	FOR(i,1,n+1)
		p2[i] += p2[i-1];
	auto getSum2 = [&](ll l, ll r) -> ll
	{
		return p2[r + 1] - p2[l];
	};
	vector<ll> p3(n+4);
	FOR(i,0,n)
		p3[i+1] = max(ar[i]-lm,0ll);
	FOR(i,1,n+1)
		p3[i] += p3[i-1];
	auto getSum3 = [&](ll l, ll r) -> ll
	{
		return p3[r + 1] - p3[l];
	};
	vector<ll> p4(n+4);
	FOR(i,0,n){
		p4[i+1] = min(ar[i]-lm,0ll);
		if(p4[i+1] < -d)
			p4[i+1] = -INF;
	}
	FOR(i,1,n+1)
		p4[i] += p4[i-1];
	auto getSum4 = [&](ll l, ll r) -> ll
	{
		return p4[r + 1] - p4[l];
	};
	vector<ll> p5(n+4);
	FOR(i,0,n)
		p5[i+1] = min(ar[i]-1,d);
	FOR(i,1,n+1)
		p5[i] += p5[i-1];
	auto getSum5 = [&](ll l, ll r) -> ll
	{
		return p5[r + 1] - p5[l];
	};
	ll ans = INF;
	ll pos = 0;
	ll cur;
	FOR(i,0,n)
	{
		ll cc = 0;
		ll cn = 0;	
		cc += getSum1(0,i-1);
		pos = max(n-(i)*(k-1),i);
		cc+= getSum5(pos,n-1);
		cc+= getSum3(i+1,pos-1);
		cn += getSum2(0,i-1);
		cn+= getSum4(i,pos-1);
		//cout << i << ' ' << pos << ' ' << cc << ' ' << cn<< endl;
		if(-cn > cc)
			continue;
		cur = -cn*t;
		cur+= i*pc;
		cur+=(pos-i)*pm;
		ans = min(ans,cur);
	}
	if(ans == INF)
		ans = -1;
	cout << ans;
	return 0;
}

int32_t main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	int TET = 1e9;
	//cin >> TET;
	for (int i = 1; i <= TET; i++)
	{
		if (solve())
		{
			break;
		}
		#ifdef ONPC
			cerr << "____________________________\n";
		#endif
	}
	#ifdef ONPC
		cerr << "\nfinished in " << clock() * 1.0 / CLOCKS_PER_SEC << " sec\n";
	#endif
}