import bisect

N = int(input())
L = list(map(int, input().split()))
K = int(input())

L.sort()

def check(x):
    print(x)
    return sum(L[i]//x for i in range(N)) >= K

l = 0
r = 1000000000

for i in range(100):
    m = (l+r)/2
    if check(m):
        l = m
    else:
        r = m

print(l)