from heapq import heappop,heappush
n,a,b,x,y = map(int,input().split())
H = list(map(int,input().split()))

def calc(k):
    h = []
    for i in H:
        if i <= k:
            continue
        heappush(h,-i+k)

    for i in range(a):
        if h:
            num = -heappop(h)
            num -= x
            if num <= 0:
                continue
            heappush(h,-num)

    count = -sum(h)
    if count <= b*y:
        return 1
    return 0


l = -1
r = 10**10
while r > l+1:
    m = (r+l)//2
    if calc(m):
        r = m
    else:
        l = m
print(r)