n = int(input())
v = sorted(list(map(lambda x: int(x), input().split())))
ans = 0
while len(v) != 1:
    a = v.pop(0)
    b = v.pop(0)
    ans = (a + b) / 2
    v.append(ans)
    v = sorted(v)
print(int(v[0]))
