from heapq import heappop,heappush
N,A,B,X,Y = map(int,input().split())
H = list(map(int,input().split()))
def is_ok(nH,nA):
    q = []
    for h in nH:
        if h > 0:
            heappush(q,-h)
    while nA and q:
        h = heappop(q)
        h *= -1
        if h > X:
            heappush(q,-(h-X))
        nA -=1
    SUMS = 0
    for h in q:
        SUMS += -h
    if SUMS <= Y * B:
        return True
    else:
        return False
ok = 10 ** 9
ng = -1
while ok - ng > 1:
    x = (ng+ok)//2
    nH = []
    for i in range(N):
        nH.append(H[i]-x)
    if is_ok(nH,A):
        ok = x
    else:
        ng = x
print(ok)