import sys 

def main():
    N = int(input())
    A = list(map(int,input().split()))
    dp = [-1]*N
    dp[0] = 0 #0が先攻が勝つ
    for i in range(1,N):
        if A[i] == 1:
            dp[i] = 1 - dp[i-1]
        else:
            dp[i] = 0
    if dp[N-1] == 0:
        print("Alice")
    else:
        print("Bob")


if __name__ == '__main__':
    main()