#include #define LLI long long int #define FOR(v, a, b) for(LLI v = (a); v < (b); ++v) #define FORE(v, a, b) for(LLI v = (a); v <= (b); ++v) #define REP(v, n) FOR(v, 0, n) #define REPE(v, n) FORE(v, 0, n) #define REV(v, a, b) for(LLI v = (a); v >= (b); --v) #define ALL(x) (x).begin(), (x).end() #define RALL(x) (x).rbegin(), (x).rend() #define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it) #define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it) #define EXIST(c,x) ((c).find(x) != (c).end()) #define fst first #define snd second #define popcount __builtin_popcount #define UNIQ(v) (v).erase(unique(ALL(v)), (v).end()) #define bit(i) (1LL<<(i)) #ifdef DEBUG #include #else #define dump(...) ((void)0) #endif #define gcd __gcd using namespace std; template constexpr T lcm(T m, T n){return m/gcd(m,n)*n;} template void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost< istream& operator>>(istream &is, vector &v){for(auto &a : v) is >> a; return is;} template void puts_all(const T &value){std::cout << value << "\n";} template void puts_all(const T &value, const Args&... args){std::cout << value << " ";puts_all(args...);} template bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);} template bool chmax(T &a, const U &b){return (a void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);} template auto make_vector(int n, int m, const T &value){return vector>(n, vector(m, value));} struct Init{ Init(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(12); cerr << fixed << setprecision(12); } }init; template class Edge{ public: int from,to; Cost cost; Edge() {} Edge(int to, Cost cost): to(to), cost(cost){} Edge(int from, int to, Cost cost): from(from), to(to), cost(cost){} Edge rev() const {return Edge(to,from,cost);} friend std::ostream& operator<<(std::ostream &os, const Edge &e){ os << "(FROM: " << e.from << "," << "TO: " << e.to << "," << "COST: " << e.cost << ")"; return os; } }; template using Graph = std::vector>>; template using Tree = std::vector>>; template void add_edge(C &g, int from, int to, T w){ g[from].push_back(Edge(from, to, w)); } template void add_undirected(C &g, int a, int b, T w){ g[a].push_back(Edge(a, b, w)); g[b].push_back(Edge(b, a, w)); } template std::vector> bridges(const Graph &graph){ int n = graph.size(); std::vector visit(n,-1), low(n,-1); std::vector> ret; int v = 0; auto dfs = [&](auto &dfs, int cur, int par) -> int{ if(visit[cur] != -1) return visit[cur]; visit[cur] = v; int temp = v; ++v; for(auto &e : graph[cur]){ if(e.to == par) continue; int t = dfs(dfs, e.to, cur); temp = std::min(temp, t); if(low[e.to] > visit[cur]) ret.push_back(e); } return low[cur] = temp; }; for(int i = 0; i < n; ++i) if(visit[i] == -1) dfs(dfs, i, -1); return ret; } template int count_connected_components(const Graph &g){ int n = g.size(); int ret = 0; vector visit(n); auto dfs = [&](auto &dfs, int cur, int par) -> void{ if(visit[cur]) return; visit[cur] = true; for(auto &e : g[cur]){ if(e.to == par) continue; dfs(dfs, e.to, cur); } }; for(int i = 0; i < n; ++i){ if(not visit[i]){ dfs(dfs, i, -1); ++ret; } } return ret; } int main(){ int N; while(cin >> N){ Graph g(N); REP(i,N-1){ int u,v; cin >> u >> v; add_undirected(g, u, v, 1); } int c = count_connected_components(g); dump(c); if(c == 1){ puts_all("Bob"); }else if(c > 2){ puts_all("Alice"); }else{ auto b = bridges(g); dump(b); if(b.empty()){ puts_all("Bob"); }else{ puts_all("Alice"); } } } return 0; }