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

low = 0
high = 1e9
for t in range(100):
    mid = (low + high) / 2
    temp = 0
    for i in range(N):
        temp += L[i] // mid
        
    if temp >= K:
        low = mid
    else:
        high = mid
        
print(low)