from heapq import *



n=int(eval(input()))

inputs=lambda:list(map(int,input().split()))

v=inputs()

u=[]

for i in v:

  heappush(u,i)

for j in range(n-1):  

  a1=heappop(u)

  a2=heappop(u)

  ave=(a1+a2)/2

  heappush(u,ave)

print((u[0]))

  
n=int(eval(input()))

v=sorted(list(map(int,input().split())),reverse=False)

#print(v)

ave=v.pop(0)

while True:

  tmp=v.pop(0) 

  ave=(ave+tmp)*0.5

  if len(v)==0:

    print(ave)

    exit()



from heapq import *

n = int(eval(input()))
inputs = lambda: list(map(int, input().split()))
v = inputs()
u = []
for i in v:
    heappush(u, i)
for j in range(n - 1):
    a1 = heappop(u)
    a2 = heappop(u)
    ave = (a1 + a2) / 2
    heappush(u, ave)
print((u[0]))

n = int(eval(input()))
v = sorted(list(map(int, input().split())), reverse=False)
# print(v)
ave = v.pop(0)
while True:
    tmp = v.pop(0)
    ave = (ave + tmp) * 0.5
    if len(v) == 0:
        print(ave)
        exit()

-from heapq import * - -inputs = lambda: list(map(int, input().split())) -v = inputs() -u = [] -for i in v: -    heappush(u, i) -for j in range(n - 1): -    a1 = heappop(u) -    a2 = heappop(u) -    ave = (a1 + a2) / 2 -    heappush(u, ave) -print((u[0])) +v = sorted(list(map(int, input().split())), reverse=False) +# print(v) +ave = v.pop(0) +while True: +    tmp = v.pop(0) +    ave = (ave + tmp) * 0.5 +    if len(v) == 0: +        print(ave) +        exit()