from functools import lru_cache

from sys import setrecursionlimit

setrecursionlimit(10 ** 6)

N, *A = map(int, open(0).read().split())

for i in range(N):
    if A[i] == 1:
        continue
    A[i] = 2


@lru_cache(maxsize=None)
def f(i, turn):
    if i == -1:
        return turn ^ 1

    if A[i - 1] == 1:
        return f(i - 1, turn ^ 1)

    t = f(i, turn ^ 1)
    if t == turn:
        return t
    return f(i - 1, turn ^ 1)


# turn = 0 Alice
# turn = 1 Bob
if f(N, 0) == 0:
    print('Alice')
else:
    print('Bob')