#include using namespace std; using int64 = long long; const int mod = 1e9 + 7; //const int mod = 998244353; const int64 infll = (1LL << 62) - 1; const int inf = (1 << 30) - 1; struct IoSetup { IoSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(10); cerr << fixed << setprecision(10); } } iosetup; template< typename T1, typename T2 > ostream &operator<<(ostream &os, const pair< T1, T2 > &p) { os << p.first << " " << p.second; return os; } template< typename T1, typename T2 > istream &operator>>(istream &is, pair< T1, T2 > &p) { is >> p.first >> p.second; return is; } template< typename T > ostream &operator<<(ostream &os, const vector< T > &v) { for(int i = 0; i < (int) v.size(); i++) { os << v[i] << (i + 1 != v.size() ? " " : ""); } return os; } template< typename T > istream &operator>>(istream &is, vector< T > &v) { for(T &in : v) is >> in; return is; } template< typename T1, typename T2 > inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); } template< typename T1, typename T2 > inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); } template< typename T = int64 > vector< T > make_v(size_t a) { return vector< T >(a); } template< typename T, typename... Ts > auto make_v(size_t a, Ts... ts) { return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...)); } template< typename T, typename V > typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) { t = v; } template< typename T, typename V > typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) { for(auto &e : t) fill_v(e, v); } template< typename F > struct FixPoint : F { FixPoint(F &&f) : F(forward< F >(f)) {} template< typename... Args > decltype(auto) operator()(Args &&... args) const { return F::operator()(*this, forward< Args >(args)...); } }; template< typename F > inline decltype(auto) MFP(F &&f) { return FixPoint< F >{forward< F >(f)}; } template< typename T > struct edge { int src, to; T cost; edge(int to, T cost) : src(-1), to(to), cost(cost) {} edge(int src, int to, T cost) : src(src), to(to), cost(cost) {} edge &operator=(const int &x) { to = x; return *this; } operator int() const { return to; } }; template< typename T > using Edges = vector< edge< T > >; template< typename T > using WeightedGraph = vector< Edges< T > >; using UnWeightedGraph = vector< vector< int > >; template< typename T > using Matrix = vector< vector< T > >; struct UnionFind { vector< int > data; UnionFind(int sz) { data.assign(sz, -1); } bool unite(int x, int y) { x = find(x), y = find(y); if(x == y) return (false); if(data[x] > data[y]) swap(x, y); data[x] += data[y]; data[y] = x; return (true); } int find(int k) { if(data[k] < 0) return (k); return (data[k] = find(data[k])); } int size(int k) { return (-data[find(k)]); } }; template< typename G > struct LowLink { const G &g; vector< int > used, ord, low; vector< int > articulation; vector< pair< int, int > > bridge; LowLink(const G &g) : g(g) {} int dfs(int idx, int k, int par) { used[idx] = true; ord[idx] = k++; low[idx] = ord[idx]; bool is_articulation = false; int cnt = 0; for(auto &to : g[idx]) { if(!used[to]) { ++cnt; k = dfs(to, k, idx); low[idx] = min(low[idx], low[to]); is_articulation |= ~par && low[to] >= ord[idx]; if(ord[idx] < low[to]) bridge.emplace_back(minmax(idx, (int) to)); } else if(to != par) { low[idx] = min(low[idx], ord[to]); } } is_articulation |= par == -1 && cnt > 1; if(is_articulation) articulation.push_back(idx); return k; } virtual void build() { used.assign(g.size(), 0); ord.assign(g.size(), 0); low.assign(g.size(), 0); int k = 0; for(int i = 0; i < g.size(); i++) { if(!used[i]) k = dfs(i, k, -1); } } }; int main() { int N; cin >> N; UnionFind uf(N); vector< int > A(N), B(N); for(int i = 1; i < N; i++) { cin >> A[i] >> B[i]; uf.unite(A[i], B[i]); } vector< int > rots; for(int i = 0; i < N; i++) { if(uf.find(i) == i) { rots.emplace_back(i); } } if(rots.size() >= 3) { cout << "Alice" << endl; return 0; } if(rots.size() == 1) { cout << "Bob" << endl; return 0; } // たぶんAliceのような気がする // え~うく vector< int > be[100000]; for(int i = 0; i < N; i++) { be[uf.find(i)].emplace_back(i); } for(int k = 0; k < 1; k++) { UnWeightedGraph g(be[rots[k]].size()); for(int i = 1; i < N; i++) { int q = uf.find(A[i]); if(q == rots[k]) { int x = lower_bound(begin(be[q]), end(be[q]), A[i]) - begin(be[q]); int y = lower_bound(begin(be[q]), end(be[q]), B[i]) - begin(be[q]); g[x].emplace_back(y); g[y].emplace_back(x); } } LowLink< UnWeightedGraph > lowLink(g); lowLink.build(); if(lowLink.bridge.size()) { cout << "Alice" << endl; return 0; } } random_device rnd; if(rnd() & 1) cout << "Bob" << endl; else cout << "Alice" << endl; }