#include <bits/stdc++.h>

typedef long long s64;

const int N = 200100;

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

int S[N];

bool check(s64 mid) {
    for (int i = 1; i <= n; i ++) S[i] = 0;

    for (int i = 1; i <= n; i ++) {
        if (a[i] >= mid) { S[1] ++; continue; }

        s64 x;
        if (d == 0) {
            if (mid - c - a[i] <= 0)
                x = 0;
            else
                x = m;
        } else {
            x = (mid - c - a[i]) / d;
            if (x < 0) x = 0;
        }

        if (x >= m) continue;
        if (i - x <= 0) continue;

        int l = std::max(1, i - m + 1), r = i - x;
        S[l] ++, S[r + 1] --;
    }

    for (int i = 1; i <= n; i ++) S[i] += S[i - 1];
    for (int i = 1; i <= n; i ++)
        if (S[i] >= k) return 1;
    
    return 0;
}

int main() {
    scanf("%d%d%d%d%d", &n, &k, &m, &c, &d);

    for (int i = 1; i <= n; i ++)
        scanf("%d", &a[i]);
    
    s64 l = 0, r = 1000000000000000000;
    while (l < r) {
        s64 mid = (l + r + 1) >> 1;
        if (check(mid)) l = mid; else r = mid - 1;
    }

    printf("%lld\n", l);

    return 0;
}