from collections import Counter

s = input().strip()
counter = Counter(s)

# 统计出现奇数次的字符数量
odd_count = sum(1 for count in counter.values() if count % 2 == 1)

# 判断胜者
if odd_count == 0 or odd_count % 2 == 1:
    print("Alice")
else:
    print("Bob")