#include using namespace std; //using namespace atcoder; struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_; #define FOR(i, begin, end) for(int i=(begin);i<(end);i++) #define REP(i, n) FOR(i,0,n) #define IFOR(i, begin, end) for(int i=(end)-1;i>=(begin);i--) #define IREP(i, n) IFOR(i,0,n) #define Sort(v) sort(v.begin(), v.end()) #define Reverse(v) reverse(v.begin(), v.end()) #define all(v) v.begin(),v.end() #define SZ(v) ((int)v.size()) #define Lower_bound(v, x) distance(v.begin(), lower_bound(v.begin(), v.end(), x)) #define Upper_bound(v, x) distance(v.begin(), upper_bound(v.begin(), v.end(), x)) #define chmax(a, b) a = max(a, b) #define chmin(a, b) a = min(a, b) #define bit(n) (1LL<<(n)) #define debug(x) cout << #x << "=" << x << endl; #define vdebug(v) { cout << #v << "=" << endl; REP(i_debug, (int)v.size()){ cout << v[i_debug] << ","; } cout << endl; } #define mdebug(m) { cout << #m << "=" << endl; REP(i_debug, (int)m.size()){ REP(j_debug, (int)m[i_debug].size()){ cout << m[i_debug][j_debug] << ","; } cout << endl;} } #define pb push_back #define fi first #define se second #define int long long #define INF 1000000000000000000 template istream &operator>>(istream &is, vector &v){ for (auto &x : v) is >> x; return is; } template ostream &operator<<(ostream &os, vector &v){ for(int i = 0; i < (int)v.size(); i++) { cout << v[i]; if(i != (int)v.size() - 1) cout << endl; }; return os; } template ostream &operator<<(ostream &os, pair p){ cout << '(' << p.first << ',' << p.second << ')'; return os; } template void Out(T x) { cout << x << endl; } template void chOut(bool f, T1 y, T2 n) { if(f) Out(y); else Out(n); } using vec = vector; using mat = vector; using Pii = pair; using v_bool = vector; using v_Pii = vector; //int dx[4] = {1,0,-1,0}; //int dy[4] = {0,1,0,-1}; //char d[4] = {'D','R','U','L'}; //const int mod = 1000000007; const int mod = 998244353; template struct edge{ int to; T cost; int id; }; template struct Graph { int N; vector>> E; vec depth, dp; Graph(int N): N(N){ E = vector>>(N, vector>(0)); depth.resize(N); dp.resize(N); } void add_Directed_edge(int from, int to, T cost = 1, int id = 0){ E[from].push_back(edge({ to, cost, id })); } void add_Undirected_edge(int v1, int v2, T cost = 1, int id = 0){ add_Directed_edge(v1, v2, cost, id); add_Directed_edge(v2, v1, cost, id); } void dfs1(int v, int d = 0, int p = -1){ depth[v] = d; for(auto e: E[v]) if(e.to != p){ dfs1(e.to, d + 1, v); } } bool dfs2(int v, const v_bool &used, int &mm, int p = -1){ bool f = false; for(auto e: E[v]) if(e.to != p){ bool f0 = used[e.id] | dfs2(e.to, used, mm, v); if(f && f0) mm = -INF; else if(f0) chmin(mm, e.cost); f = f || f0; } return f; } }; signed main(){ int N; cin >> N; Graph G(N); vec a(N - 1), b(N - 1), c(N - 1); int cmax = 0; REP(i, N - 1){ cin >> a[i] >> b[i] >> c[i]; a[i]--; b[i]--; G.add_Undirected_edge(a[i], b[i], c[i], i); chmax(cmax, c[i]); } G.dfs1(0); int ok = cmax, ng = -1; while(ok - ng > 1){ int x = (ng + ok) / 2; v_bool used(N - 1, false); int d0 = -1, v0 = -1; REP(i, N - 1) if(c[i] > x){ used[i] = true; for(int s: {a[i], b[i]}) if(G.depth[s] > d0){ d0 = G.depth[s]; v0 = s; } } int mm = INF; G.dfs2(v0, used, mm); if(cmax - mm <= x) ok = x; else ng = x; } cout << ok << endl; return 0; }