n = int(input())
value = [int(i) for i in input().split()]

now = 0
a = sorted(value) ##value.sort() だとvalueで2行目を参照してしまう？

while len(a) >= 2:
  a = sorted(a)
  print(a)
  now = (float(a[0]) + float(a[1])) / float(2)
  print(now)
  if len(a) >= 3:
    del a[0],a[0] ##a[0],a[1]にしてた
    a.append(now)
  elif len(a) == 2:
    print(now)
    break
    