N = gets.to_i
L = gets.split.take(N).map(&:to_i)
K = gets.to_i
start = 0.0
last = L.sum.quo(K).ceil * 1.0

count = 0
ans = (start..last).bsearch{|_i|
  i = last - _i
  sum = L.map{|l| (l / i).floor }.sum
  count += 1
  sum >= K
}
p last - ans