from collections import defaultdict
from random import randint

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

f.append(0)

idx = set(range(n))

turn = 0
while idx:
    i = idx.pop()
    if f[i] == 0: continue
    l ,r = i, i+1
    while f[l-1] != 0: l -= 1
    while f[r] != 0: r += 1
    
    cnt = defaultdict(int)
    for j in range(l, r):
        cnt[f[j]] += 1
    
    for c, v in cnt.items():
        if v == 1:
            break
    else:
        continue
    
    for j in range(l, r):
        if f[j] == c:
            break
    
    idx.add(i)
    f[j] = 0
    idx.discard(j)
    turn ^= 1

print("Alice" if turn else "Bob")