#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> template void debug(T e) { cerr << e << endl; } template void debug(vector &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(map &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } using mint = modint998244353; void debug_mint1(vector &vec) { for (int i = 0; i < vec.size(); i++) { cerr << vec[i].val() << " "; } cerr << endl; } void debug_mint2(vector> &vec) { for (int i = 0; i < vec.size(); i++) { for (int j = 0; j < vec[i].size(); j++) { cerr << vec[i][j].val() << " "; } cerr << endl; } } ll INF = 100000002LL; void dfs(vector> &graph, vector &isvisited, ll v, vector &dp1, vector &dp2){ isvisited[v] = true; // 1: 過半数の個数を 1 で、残りを 2 の方法で塗り、自身は 2 の方法で塗る // または、自身は 1 の方法で塗る代わりにその子は 2 の方法で塗る // 2: 過半数 - 1 の個数を 1 で、残りを 2 の方法で塗り、自身は 2 の方法で塗る vector p; for (ll x: graph[v]){ if (isvisited[x]) continue; dfs(graph, isvisited, x, dp1, dp2); p.push_back(make_pair(dp1[x] - dp2[x], dp2[x])); } sort(all(p)); reverse(all(p)); // debug(v); // debug(p); ll len_v = graph[v].size(); ll len_p = p.size(); ll v11, v12, v2; // まず v2 から求める v2 = 0; for (ll i = 0; i < len_p - len_v / 2; i++){ v2 += p[i].second; } for (ll i = len_p - len_v / 2; i < len_p; i++){ v2 += (p[i].first + p[i].second); } dp2[v] = min(dp2[v], v2); v12 = 1; for (ll i = 0; i < len_p; i++){ v12 += p[i].second; } dp1[v] = min(dp1[v], v12); // 次に v1 を求めよう if ((len_v + 1) / 2 <= len_p){ for (ll i = 0; i < len_p - (len_v + 1) / 2; i++){ v11 += p[i].second; } for (ll i = len_p - (len_v + 1) / 2; i < len_p; i++){ v11 += (p[i].first + p[i].second); } dp1[v] = min(v11, dp1[v]); } // debug_out(v, v11, v12, v2); return; } int main() { ll N; cin >> N; vector u(N - 1); vector v(N - 1); rep(i, N - 1){ cin >> u[i] >> v[i]; u[i]--; v[i]--; } vector> graph(N, vector(0)); rep(i, N - 1){ graph[u[i]].push_back(v[i]); graph[v[i]].push_back(u[i]); } vector dp1(N, INF); vector dp2(N, INF); vector isvisited(N, false); dfs(graph, isvisited, 0, dp1, dp2); // debug(dp1); // debug(dp2); cout << dp1[0] << endl; }