# n = 10
# dp = [0] * (1 << n)
# for s in range(1 << n):
#     win = False
#     for k in range(n):
#         if s >> k & 1 == 0:
#             continue
#         ns = s ^ 1 << k
#         win |= dp[ns] == 0
#         for i in range(k)[::-1]:
#             if ns >> i & 1 == 1:
#                 break
#             ns |= 1 << i
#             win |= dp[ns] == 0
#     dp[s] = win
# for s in range(1 << 6):
#     print(f'{s:010b}', dp[s])

n = int(input())
s = input()
v = 0
for c in reversed(s):
    v = (2 * v + (c == 'B')) % 3
print('Alice' if v else 'Bob')