import sys
input = sys.stdin.readline
N = int(input())
a = list(map(int, input().split()))

dp = [0] * (N + 1)
for i in range(N):
  if dp[i] == 0: dp[i + 1] = 1
  else:
    if a[i] == 1: dp[i + 1] = 0
    else: dp[i + 1] = 1
#print(dp)

if dp[-1]: print("Alice")
else: print("Bob")