from sys import stdin

N = int(stdin.readline().rstrip())
V = [float(x) for x in stdin.readline().rstrip().split()]

V.sort(reverse=True)
ans = 0

while len(V) > 1:
    ans += (V[len(V) - 1] + V[len(V) - 2]) / 2
    new = (V[len(V) - 1] + V[len(V) - 2]) / 2
    V.pop()
    V.pop()
    V.append(new)
    print(V)

print(V[0])
