import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N = int(input())
	L = [0] * N
	for i in range(N):
		a, b = getlist()
		L[a] += 1; L[b] += 1

	cnt = 0
	for i in L:
		if i <= 1:
			cnt += 1

	if cnt >= 3:
		print("Alice")
	else:
		print("Bob")

if __name__ == '__main__':
	main()