N = int(input())
A = list(map(lambda x: min(2,int(x)), input().split()))
dp = [[0]*3 for _ in range(N)]
def mex(lis):
  for i in range(4):
    if i not in lis:
      return i
for i in range(N):
  if i>0:
    dp[i][0] = dp[i-1][A[i-1]]
  for j in range(1,A[i]+1):
    dp[i][j] = mex(dp[i][:j])
print("Alice" if dp[-1][A[-1]]>0 else "Bob")