N = int(input())
a = list(map(int,input().split()))

def ave(c1,c2):
  av = (c1 + c2)/2
  return av

for i in range(N-1):
  for j in range(i+1,N):
    if a[j] <= a[i]:
      tmp = a[i]
      a[i] = a[j]
      a[j] =tmp
for i in range(N-1):
  average = ave(a[0],a[1])
  a.pop(0)
  a.pop(0)
  a.insert(0,average)

print(int(a[0]))