n, a, b, x, y = map(int,input().split())
h = list(map(int,input().split()))
def solve(n, a, b, x, y, h):
    h.sort()
    from collections import deque
    def check(k):
        q1 = deque()
        q2 = deque()
        for i in range(n):
            q1.appendleft(max(h[i] - k, 0))
        for _ in range(a):
            now = 0
            if not q1:
                now = q2.pop()
            elif not q2:
                now = q1.pop()
            
            elif q1[-1] > q2[-1]:
                now = q1.pop()
            else:
                now = q2.pop()
            now = max(now - x, 0)
            q2.appendleft(now)
        if sum(q1) + sum(q2) <= b * y:
            return True
        else:
            return False
    ok = 10 ** 9
    ng = -1

    while abs(ok - ng) > 1:
        mid = (ok + ng) // 2
        if check(mid):
            ok = mid
        else:
            ng = mid
    return ok
print(solve(n, a, b, x, y, h))