from collections import deque
n = int(input())
v = [int(i) for i in input().split()]
v.sort()
vi = deque(v)
while len(vi) != 1:
	v0 = vi.popleft()
	v1 = vi.popleft()
	vadd = (v0+v1)/2
	vi.appendleft(vadd)
print(int(vi[0]))
