class UnionFind: def __init__(self, n): self.parent = [-1] * n self.cnt = n self.n = n def root(self, x): """頂点xの根を求める""" if self.parent[x] < 0: return x else: self.parent[x] = self.root(self.parent[x]) return self.parent[x] def merge(self, x, y): """頂点xを含む集合と頂点y含む集合を結合する""" x = self.root(x) y = self.root(y) if x != y: if self.parent[x] > self.parent[y]: x, y = y, x self.parent[x] += self.parent[y] self.parent[y] = x self.cnt -= 1 def is_same(self, x, y): """頂点xと頂点yが同じ集合に属するかどうかを返す""" return self.root(x) == self.root(y) def get_size(self, x): """頂点xを含む集合の要素数を返す""" return -self.parent[self.root(x)] def get_cnt(self): """木の個数を返す""" return self.cnt def members(self, x): """頂点xが属する集合の要素を列挙する 計算量に注意""" root_x = self.root(x) return [i for i in range(self.n) if self.root(i) == root_x] n = int(input()) info = [list(map(int, input().split())) for i in range(n - 1)] tree = [[] for i in range(n)] for i in range(n - 1): a, b = info[i] tree[a].append(b) tree[b].append(a) uf = UnionFind(n) for i in range(n - 1): a, b = info[i] uf.merge(a, b) if uf.get_cnt() == 1: print("Bob") elif uf.get_cnt() == 2: for i in range(n): if not(len(tree[i]) == 2 or len(tree[i]) == 0): print("Alice") break else: print("Bob") else: print("Alice")