import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

def Binary_Search(L, N, K):
	#初期化
	left = 0
	right = 10 ** 9
	ans = 0
	
	#二分探索
	for i in range(70):
		mid = (left + right) / 2
		val = 0
		for j in L:
			val += int(j // mid)
		if val >= K:
			ans = max(ans, mid)
			left = mid
		else:
			right = mid

	return ans

#処理内容
def main():
	N = int(input())
	L = getlist()
	K = int(input())
	ans = Binary_Search(L, N, K)
	print(ans)
	




if __name__ == '__main__':
	main()