import sys


def input(): return sys.stdin.readline().rstrip()


def main():
    M = int(input())
    S = [int(input()) for i in range(1 << M)]
    prob = [[(i, 1)] for i in range(1 << M)]

    while len(prob) > 1:

        def merge(A, B):
            ret = {}
            for a, x in A:
                for b, y in B:
                    ret[a] = ret.get(a, 0) + x*y * \
                        (S[a]*S[a])/(S[a]*S[a]+S[b]*S[b])
                    ret[b] = ret.get(b, 0) + x*y * \
                        (S[b]*S[b])/(S[a]*S[a]+S[b]*S[b])

            return list(ret.items())

        prob = [merge(prob[i], prob[i+1]) for i in range(0, len(prob), 2)]

    for x, y in prob[0]:
        if x == 0:
            print(y)


if __name__ == '__main__':
    main()