def General_Binary_Increase_Search_Integer(L,R,cond,default=None):
    """条件式が単調増加であるとき, 整数上で二部探索を行う.
    L: 解の下限
    R: 解の上限
    cond: 条件(1変数関数, 広義単調増加を満たす)
    default: Lで条件を満たさないときの返り値
    """
    if not(cond(R)): return default

    if cond(L): return L

    R+=1
    while R-L>1:
        C=L+(R-L)//2
        if cond(C): R=C
        else: L=C
    return R
#==================================================
from heapq import heapify,heappop,heappush

def check(K):
    HH=[-(hp-K) for hp in H if hp>K]
    heapify(HH)

    for _ in range(A):
        if not HH:
            continue

        hp=-heappop(HH)
        if hp>=X:
            heappush(HH,-(hp-X))
    return -sum(HH)<=Y*B
#==================================================
N,A,B,X,Y=map(int,input().split())
H=list(map(int,input().split()))

print(General_Binary_Increase_Search_Integer(0,max(H),check,-1))