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

right = N - 1
count = 0
while right >= 0 and A[right] == -1:
    right -= -1
    count += 1
if count == N:
    if N % 2 == 1:
        print('Alice')
    else:
        print('Bob')
else:
    if count % 2 == 1:
        print('Bob')
    else:
        print('Alice')