#1506 Unbalanced Pocky Game

n=int(input())
A=list(map(int,input().split()))

cntCont=0
isReverse=False
for el in A:
    if el==1:
        cntCont+=1
    else:
        if cntCont>1 and cntCont%2==0:
            isReverse=not isReverse
        cntCont=0

if A[-1]!=1:
    if not isReverse:
        print('Alice')
    else:
        print('Bob')
else:
    if not isReverse:
        print('Bob')
    else:
        print('Alice')