#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <array>
#include <random>
#include <cmath>
#include <chrono>
#include <list>
#include <ctime>
#include <sstream>
#include <queue>
#include <climits>
#include <stack>
#include <valarray>
#include <random>
#include <bitset>
#include <numeric>
#include <iomanip>
#include <cassert>
using namespace std;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef long long ll;
#define rep(x, b, e) for(int x=(b); x<(e); ++x)
#define trav(a, x) for(auto& a : x)
#define ford(x, b, e) for(int x=((int)(b))-1; x>=(e); --x)
#define all(c) c.begin(),c.end()
#define sz(x) ((int)((x).size()))
#define pb push_back
#define eb emplace_back
#define st first
#define nd second
#define mp(x,y) make_pair(x,y)
typedef short int sint;
template<typename T> bool ckmin(T& a, const T& b){return b<a?a=b,1:0;}
template<typename T> bool ckmax(T& a, const T& b){return b>a?a=b,1:0;}


template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(char c) {
  return string(1, c);
}

string to_string(const char* s) {
  return to_string((string) s);
}

string to_string(bool b) {
  return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif


// #include <atcoder/modint>
// using namespace atcoder;
// using mint = modint998244353; // modint1000000007;
// typedef vector<mint> vmi;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); // use rng() to get unsigned int
// mt19937_64 for random long longs

const int N = 2e5 + 10;
const ll inf = 1e18;
vector<pii> gr[N];
ll res[N][4];
ll f[N][2][4], g[N][2][4];
vector<pii> children[N];

// void wyp(int v, string dopisek) {
//   debug(dopisek, v, f[v][0], f[v][1], f[v][2], f[v][3]);
// }

void go(int v, int par) {
  for (auto [u, z] : gr[v]) {
    if (u == par) continue;
    go(u, v);
    children[v].eb(u, z);
  }

  int fsz = 1;
  rep(i, 0, 2) rep(j, 0, 4) f[0][i][j] = -inf;
  f[0][0][0] = 0;
  rep(i, 0, sz(children[v])) {
    int gsz = 2 * (i + 1) + 1;
    rep(q, 0, gsz) rep(w, 0, 2) rep(e, 0, 4) g[q][w][e] = -inf;
    auto [u, z] = children[v][i];
    debug("have child: ", u, z);
    rep(one_min_to, 0, fsz) {
      int one_min_to_new_posistion = one_min_to + 1;
      rep(one_mod, 0, 2) {
        rep(j, 0, 4) {
          ll pre = f[one_min_to][one_mod][j];
          if (pre == -inf) {
            continue;
          }
          debug("updating: ", v, one_min_to, one_mod, j);

          if (res[u][0] != -inf) {
            // add only res[u][0] with no edge
            ckmax(g[one_min_to_new_posistion][one_mod][j], pre + res[u][0]);

            // add res[u][0] with edge
            ckmax(g[one_min_to_new_posistion + 1][one_mod][j], pre + res[u][0] + z);
          }

          if (res[u][1] != -inf) {
            // add res[u][1] with edge
            ckmax(g[one_min_to_new_posistion][(one_mod + 1)%2][j], pre + res[u][1] + z);
          }

          if (res[u][2] != -inf) {
            // add res[u][2] with edge
            ckmax(g[one_min_to_new_posistion - 1][one_mod][j], pre + res[u][2] + z);
          }

          if (res[u][3] != -inf) {
            // add res[u][3] with edge
            ckmax(g[one_min_to_new_posistion][one_mod][j], pre + res[u][3] + z);
          }
        }

        ll pre = f[one_min_to][one_mod][0];
        if (pre == -inf) continue;
        if (res[u][0] != -inf) {
          // add res[u][0] with edge as the special arg for res[v][1]
          ckmax(g[one_min_to_new_posistion][one_mod][1], pre + res[u][0] + z);
        }

        if (res[u][1] != -inf) {
          // add res[u][1] with edge as the special arg for res[v][2]
          ckmax(g[one_min_to_new_posistion][one_mod][2], pre + res[u][1] + z);
        }

        if (res[u][2] != -inf) {
          // add res[u][2] with edge as the special arg for res[v][3]
          ckmax(g[one_min_to_new_posistion][one_mod][3], pre + res[u][2] + z);
        }
      }
    }
    fsz = gsz;
    rep(q, 0, gsz) rep(w, 0, 2) rep(e, 0, 4) f[q][w][e] = g[q][w][e];
    // f = g;
  }

  // debug(v, f);
  rep(j, 0, 4) {
    res[v][j] = f[sz(children[v])][0][j];
  }
  debug(v, res[v][0], res[v][1], res[v][2], res[v][3]);
}

void solve() {
	int n;
  scanf("%d", &n);
  rep(i, 0, n - 1) {
    int u, v, z;
    scanf("%d %d %d", &u, &v, &z);
    gr[u].eb(v, z);
    gr[v].eb(u, z);
  }
  go(1, -1);
  printf("%lld\n", res[1][0]);
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	int t;
	// cin >> t;
	t = 1;
	while (t--) {
		solve();
	}
}