#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define rep(i,n) for(int i=0;i<(n);i++) #define all(x) x.begin(), x.end() #define rall(x) x.rbegin(), x.rend() #define sz(x) ((int)(x).size()) #define pb push_back #define mod 1000000007 using ll = long long; using namespace std; ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;} ll lcm(ll a, ll b) {return a/gcd(a,b)*b;} int main(){ int N; cin >> N; vector> tree(N); int a,b; rep(i,N-1){ cin >> a >> b; tree[a].pb(b); tree[b].pb(a); } int cnt0 = 0, cnt2 = 0; rep(i,N) { if(sz(tree[i])==0) cnt0++; else if(sz(tree[i])==2) cnt2++; } vector d(N,-1); queue q; int st = 0; q.push(st); d[st] = 0; while(!q.empty()){ int now = q.front(); q.pop(); rep(i,sz(tree[now])){ if(d[tree[now][i]]>=0) continue; q.push(tree[now][i]); d[tree[now][i]] = d[now]+1; } } bool chain = true; rep(i,N) { if(d[i]<0) { chain = false; st = i; } } if(chain){ cout << "Bob" << endl; return 0; } q.push(st); d[st] = 0; while(!q.empty()){ int now = q.front(); q.pop(); rep(i,sz(tree[now])){ if(d[tree[now][i]]>=0) continue; q.push(tree[now][i]); d[tree[now][i]] = d[now]+1; } } rep(i,N){ if(d[i]<0){ cout << "Alice" << endl; return 0; } } if(cnt0 == 1 && cnt2 == N-1) cout << "Bob" << endl; else cout << "Alice" << endl; return 0; }