from heapq import heapify, heappush, heappop
n, a, b, x, y = map(int, input().split())
h = list(map(lambda x:-int(x), input().split()))
heapify(h)
for i in range(a):
    xx = -heappop(h)
    xx -= x
    heappush(h, -xx)
h = list(map(lambda x:-x, h))
l, r = 0, 1000000000
while r - l > 1:
    m = (l + r) // 2
    hh = list(map(lambda x:x-m, h))
    t = b * y
    for i in range(n):
        d = max(0, min(hh[i], t))
        hh[i] -= d
        t -= d
    for i in range(n):
        if hh[i] > 0:
            l = m
            break
    else:
        r = m
print(r)