import bisect



def main():

    N = int(eval(input()))

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

    while len(v) > 1:

        num1 = v.pop(0)

        num2 = v.pop(0)

        avg = (num1 + num2) / 2

        idx = bisect.bisect(v, avg)

        v.insert(idx, avg)

    print((v[0]))

main()
n=int(eval(input()))

v=list(map(int,input().split()))

v.sort()

a=(v[0]+v[1])/2

for i in range(2,n):

    a=(a+v[i])/2

print(a)
import bisect


def main():
    N = int(eval(input()))
    v = sorted(list(map(int, input().split())))
    while len(v) > 1:
        num1 = v.pop(0)
        num2 = v.pop(0)
        avg = (num1 + num2) / 2
        idx = bisect.bisect(v, avg)
        v.insert(idx, avg)
    print((v[0]))


main()

n = int(eval(input()))
v = list(map(int, input().split()))
v.sort()
a = (v[0] + v[1]) / 2
for i in range(2, n):
    a = (a + v[i]) / 2
print(a)

-import bisect - - -def main(): -    N = int(eval(input())) -    v = sorted(list(map(int, input().split()))) -    while len(v) > 1: -        num1 = v.pop(0) -        num2 = v.pop(0) -        avg = (num1 + num2) / 2 -        idx = bisect.bisect(v, avg) -        v.insert(idx, avg) -    print((v[0])) - - -main() +n = int(eval(input())) +v = list(map(int, input().split())) +v.sort() +a = (v[0] + v[1]) / 2 +for i in range(2, n): +    a = (a + v[i]) / 2 +print(a)