#!usr/bin/env python3
from collections import defaultdict, deque
from heapq import heappush, heappop
from itertools import permutations, accumulate
import sys
import math
import bisect
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def I(): return int(sys.stdin.readline())
def IR(n):
    return [I() for _ in range(n)]
def LIR(n):
    return [LI() for _ in range(n)]

sys.setrecursionlimit(1000000)
mod = 1000000007

def main():
    def f(k):
        h = [i-k for i in h_]
        q = []
        for i in h:
            if i > 0:
                heappush(q,-i)
        for _ in range(a):
            if not q:
                break
            i = heappop(q)
            i += x
            if i < 0:
                heappush(q,i)
        s = -sum(q)
        return s <= b*y

    n,a,b,x,y = LI()
    h_ = LI()
    l = -1
    r = 10**9+1
    while l+1 < r:
        k = (l+r) >> 1
        if f(k):
            r = k
        else:
            l = k
    print(r)
    return


if __name__ == "__main__":
    main()