n = int(input())
a = list(map(int, input().split()))
if a[-1] != 1: exit(print("Alice"))
ans = 0
for i in range(n)[::-1]:
    if a[i] == 1:
        ans ^= 1
    else:
        exit(print(["Alice", "Bob"][ans]))
print(["Alice", "Bob"][ans])