class UnionFind: def __init__(self, n): self.parent = list(range(n)) #親ノード self.size = [1]*n #グループの要素数 def root(self, x): #root(x): xの根ノードを返す. while self.parent[x] != x: self.parent[x] = self.parent[self.parent[x]] x = self.parent[x] return x def merge(self, x, y): #merge(x,y): xのいる組とyのいる組をまとめる x, y = self.root(x), self.root(y) if x == y: return False if self.size[x] < self.size[y]: x,y=y,x #xの要素数が大きいように self.size[x] += self.size[y] #xの要素数を更新 self.parent[y] = x #yをxにつなぐ return True def issame(self, x, y): #same(x,y): xとyが同じ組ならTrue return self.root(x) == self.root(y) def getsize(self,x): #size(x): xのいるグループの要素数を返す return self.size[self.root(x)] # coding: utf-8 # Your code here! import sys readline = sys.stdin.readline read = sys.stdin.read n = int(input()) res = [0]*n UF = UnionFind(n) cnt = n for _ in range(n-1): a,b = [int(i) for i in readline().split()] res[a] += 1 res[b] += 1 if UF.merge(a,b): cnt -= 1 d = res.count(1) if cnt >= 3: print("Alice") elif cnt == 1: print("Bob") else: if d == 0: print("Alice") else: print("Bob")