mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    N = int(input())
    A = list(map(int, input().split()))

    flg = 0
    for a in A[::-1]:
        if a != 1:
            flg += 2
            break
        else:
            flg ^= 1
    if flg == 2:
        print("Alice")
    elif flg == 3:
        print("Bob")
    elif flg == 0:
        print("Bob")
    elif flg == 1:
        print("Alice")


if __name__ == '__main__':
    main()