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(N): 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")