#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
int main() {
ios::sync_with_stdio(0), cin.tie(0);
int n, m, k; cin >> n >> m >> k;
LL a, b, c; cin >> a >> b >> c;
long long t; cin >> t;
vector<LL> s(m), p(m - 1); for (LL& x : s) cin >> x;
priority_queue<pair<LL, int>> pq;
LL ans = b * (n - 1) <= t ? 0 : -1;
for (int i = 0; i < m - 1; i++) {
if (b * (s[i] - 1) > t) continue;
LL u = min(s[i + 1] - 1, s[i] + (t - b * (s[i] - 1)) / a);
ans += u - s[i] + 1;
p[i] = u + 1;
if (p[i] < s[i + 1] && b * (s[i] - 1) + c * (p[i] - s[i]) <= t)
pq.push({min(s[i + 1] - 1, p[i] + (t - b * (s[i] - 1) - c * (p[i] - s[i])) / a) - p[i] + 1, i});
}
for (int it = 0; it < k - m; it++) {
if (pq.empty()) break;
auto [v, i] = pq.top(); pq.pop();
ans += v, p[i] += v;
if (p[i] < s[i + 1] && b * (s[i] - 1) + c * (p[i] - s[i]) <= t)
pq.push({min(s[i + 1] - 1, p[i] + (t - b * (s[i] - 1) - c * (p[i] - s[i])) / a) - p[i] + 1, i});
}
cout << ans << '\n';
return 0;
}
