#include <bits/stdc++.h>
#ifndef ONLINE_JUDGE
#include "_my_utils.h"
#endif
#define int long long

using namespace std;
using ll = long long;
using PII = std::pair<int, int>;

constexpr ll INF = 2E18 + 10;
constexpr int N = 2E5 + 10;

int n, k, m, c, d;
int a[N];

int b[N];

bool check(int x) {
    for (int i = 1; i <= n; i++) {
        a[i] = b[i];
    }
    vector<int> pr(n + 10, 0);
    for (int i = 1; i <= n; i++) {
        if (a[i] >= x) {
            pr[1]++;
            pr[n + 1]--;
        } else if (a[i] + c + d * (min(i, m) - 1) >= x) {
            if(d==0){
                pr[max(1LL, i - m + 1)]++;
                pr[i + 1]--;
                continue;
            }
            pr[max(1LL, i - m + 1)]++;
            int mx = a[i] + c + d * (min(i, m) - 1);
            int cnt = (mx - x + d - 1) / d;
            pr[max(1LL,i-m+1) + cnt + 1]--;
        }
    }
    int t = 0;
    for (int i = 1; i + m - 1 <= n; i++) {
        t += pr[i];
        if (t >= k) {
            return 1;
        }
    }
    return 0;
}

void SINGLE_TEST() {
    cin >> n >> k >> m >> c >> d;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        b[i] = a[i];
    }

    int l = 0, r = INF;
    while (l < r) {
        int mid = (l + r + 1) / 2;
        if (check(mid)) {
            l = mid;
        } else {
            r = mid - 1;
        }
    }
    cout << l << "\n";
}

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

    int SAMPLES = 1;
    // cin >> SAMPLES;
    for (int CUR = 1; CUR <= SAMPLES; CUR++) {
        SINGLE_TEST();
    }
}