func_code_string: #include <bits/stdc++.h>   using namespace std;   struct EDGE {     int to, next, w;   } e[400010];   int head[200010], top;   void add(int u, int v, int w) {     e[top].to = v;     e[top].next = head[u];     e[top].w = w;     head[u] = top++;   }   vector<int> vv;   int vis[200010], tmpp = -1;   long long in_max;   int fa[200010], id[400010];   long long dep[200010];   long long l[400010], r[400010], wl[400010], idtop, val[400010];   vector<int> o;   void dfs(int x, int fa) {     if (vis[x]) {       tmpp = x;       throw  w23c3c3 ;     }     vis[x] = 1;     vv.push_back(x);     int i;     for (i = head[x]; ~i; i = e[i].next) {       if (e[i].to == fa) continue;       o.push_back(e[i].w);       dfs(e[i].to, x);       o.pop_back();     }     vv.pop_back();   }   void dfs1(int x) {     int i;     long long max_ = 0, se = 0, tmp;     for (i = head[x]; ~i; i = e[i].next) {       if (vis[e[i].to] || e[i].to == fa[x]) continue;       fa[e[i].to] = x;       dfs1(e[i].to);       tmp = dep[e[i].to] + e[i].w;       if (tmp > max_) {         se = max_;         max_ = tmp;       } else {         if (tmp > se) {           se = tmp;         }       }     }     in_max = max(in_max, max_ + se);     dep[x] = max_;   }   struct __ {     int id;     long long val;     bool operator<(const __ &ob) const {       if (val != ob.val) return val > ob.val;       return id < ob.id;     }   };   multiset<__> L, R;   int main() {     memset(head, 255, sizeof(head));     int n;     scanf( %d , &n);     int i;     int u, v, w;     for (i = 1; i <= n; i++) {       scanf( %d%d%d , &u, &v, &w);       add(u, v, w);       add(v, u, w);     }     int tmp;     try {       dfs(1, 0);     } catch (...) {     }     tmp = tmpp;     memset(vis, 0, sizeof(vis));     int len = 1;     wl[idtop] = o.back();     o.pop_back();     id[idtop++] = tmp;     vis[tmp] = 1;     while (1) {       if (vv.back() == tmp) break;       len++;       wl[idtop] = o.back();       o.pop_back();       id[idtop++] = vv.back();       vv.pop_back();       vis[id[idtop - 1]] = 1;     }     vv.clear();     for (i = 1; i <= n; i++) {       if (vis[i]) {         dfs1(i);       }     }     for (i = 0; i < len; i++) {       val[i] = dep[id[i]];     }     for (i = 0; i < len; i++) {       id[i + len] = id[i];       wl[i + len] = wl[i];       val[i + len] = val[i];     }     l[0] = r[0] = val[0];     for (i = 1; i < (len << 1) - 1; i++) {       l[i] = l[i - 1] - val[i - 1] - wl[i - 1] + val[i];       r[i] = r[i - 1] - val[i - 1] + wl[i - 1] + val[i];     }     long long ans = 998244353998244347;     for (i = 0; i < len - 1; i++) {       L.insert((__){id[i], l[i]});       R.insert((__){id[i], r[i]});     }     __ tmpl1, tmpl2, tmpr1, tmpr2;     for (i = len - 1; i + 1 < len << 1; i++) {       L.insert((__){id[i], l[i]});       R.insert((__){id[i], r[i]});       tmpl1 = *L.begin();       tmpl2 = *++L.begin();       tmpr1 = *R.begin();       tmpr2 = *++R.begin();       if (tmpl1.id != tmpr1.id) {         ans = min(ans, max(in_max, tmpl1.val + tmpr1.val));       } else {         ans = min(ans,                   max(in_max, max(tmpl1.val + tmpr2.val, tmpl2.val + tmpr1.val)));       }       L.erase(L.lower_bound((__){id[i - (len - 1)], l[i - (len - 1)]}));       R.erase(R.lower_bound((__){id[i - (len - 1)], r[i - (len - 1)]}));     }     printf( %lld n , ans);     return 0;   }   