N = int(input())
S = input()

if("B" not in S):
    print("Bob")
    exit()

if("AA" in S):
    print("Alice")
    exit()

S = S[::-1]
SUM = 0
for i in range(N):
    SUM += i * (S[i] == "A")
print("Alice" if SUM%2 == 1 else "Bob")