n=int(input())
L=list(map(int,input().split()))
k=int(input())

def check(x):
    cnt=0
    for l in L:
        cnt+=l//x
    return cnt

cnt=0
ok,ng=0,10**18
while cnt<=1000:
    cnt+=1
    mid=(ok+ng)/2
    if check(mid)>=k:ok=mid
    else:ng=mid
    

print(ok)