# region template
import sys
import typing
from typing import Callable, Dict, List, Set, Tuple
import heapq
from operator import itemgetter

sys.setrecursionlimit(10 ** 6)
Vec = List[int]
VecVec = List[Vec]
sinput: Callable[..., str] = sys.stdin.readline
MOD: int = 1000000007
INF: float = float("Inf")
IINF: int = sys.maxsize
# endregion


def meguru_bisect(ok: int, ng: int, is_ok: Callable[..., bool], *args) -> int:
    """二分探索法
    Args:
        ok (int): is_okを満たす初期値
        ng (int): is_okを満たさない初期値
        is_ok (typing.Callable[..., bool]): 判定用関数
        *args (object): is_okに渡される引数
    Returns:
        int: is_okを満たす最大/小の整数
    """
    assert is_ok(ok, *args)
    assert not is_ok(ng, *args)

    while abs(ok - ng) > 1:
        mid = (ok + ng) >> 1
        if is_ok(mid, *args):
            ok = mid
        else:
            ng = mid
    return ok


def main() -> None:
    n, a, b, x, y = map(int, sinput().split())
    h = tuple(map(int, sinput().split()))

    def ok(th: int) -> bool:
        if th < 0:
            return False
        rem_b = y * b
        que = [(-h[i] + th, i) for i in range(n)]
        heapq.heapify(que)
        for _ in range(a):
            top, i = heapq.heappop(que)
            top += x
            heapq.heappush(que, (top, i))

        que.sort(key=itemgetter(1))

        for hi, _ in que:
            hi *= -1

            if hi >= 0:
                if hi > rem_b:
                    return False
                else:
                    rem_b -= hi

        return True

    print(meguru_bisect(max(h), -1, ok))


if __name__ == "__main__":
    main()