#include <bits/stdc++.h>
#define int long long

using namespace std;

constexpr int MAXN = 200005;
int n, k, m, c, d, a[MAXN];

bool check(int x) {
    vector <int> pre(n + 1, 0);
    for(int i = 1; i <= n; i++) {
        if(a[i] >= x) {
            pre[1]++;
        } else if(a[i] + c + min(m - 1, i - 1) * d >= x) {
            pre[max(1ll, i - m + 1)]++;
            int cnt = 0;
            if(d != 0) {
                cnt = (x - a[i] - c + d - 1) / d;
            }
            pre[min(i, i - cnt) + 1]--;
        }
    }

    for(int i = 1; i <= n - m + 1; i++) {
        pre[i] += pre[i - 1];
        if(pre[i] >= k) {
            return true;
        }
    }

    return false;
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> n >> k >> m >> c >> d;

    for(int i = 1; i <= n; i++) {
        cin >> a[i];
    }

    int l = 0, r = 4E14;
    while(l < r) {
        int mid = (l + r) / 2;
        if(check(mid)) {
            l = mid + 1;
        } else {
            r = mid;
        }
    }

    cout << r - 1 << '\n';

    return 0;
}