#include <bits/stdc++.h>
#define test(x) cout << #x <<" = " << x << endl
#define int long long
#define vint vector<int>
#define endl "\n"
using namespace std;
const int N = 2e5 + 5;

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

int Cal(int x) {
    vint b(n + 2);
    for (int i = 1; i <= n; ++i) {
        if (a[i] >= x)
            b[1]++;
        else if (a[i] + min(i, m) * d + c >= x) {
            b[max(1ll, i - m + 1)]++;
            if (!d) {
                b[i+1]--;
            }
            else {
                int tt = (x - a[i] - c - 1) / d + 1;
                b[i-tt+2]--;
            }
        }
    }
    int ans = 0, t = 0;
    for (int i = 1; i <= n; ++i) {
        t += b[i];
        ans = max(ans, t);
    }
    return ans;
}

void sol(){
    cin >> n >> k >> m >> c >> d;
    // vint a(n + 1);
    for (int i = 1; i <= n; ++i)
        cin >> a[i];
    int l = 0, r = 1e18, mid;
    while (l < r) {
        int mid = (l + r + 1) >> 1;
        if (Cal(mid) >= k) l = mid;
        else r = mid - 1;
    }
    cout << l << endl;
}

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int T = 1;
    // cin >> T;
    while(T--) {
        sol();
    }
    return 0;
}
/*

*/