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

dp = [True] * n
for i in range(1, n):
    if A[i] == 1:
        dp[i] = dp[i - 1] ^ True
    else:
        dp[i] = True
        
if dp[-1]:
    print("Alice")
else:
    print("Bob")