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#include <bits/stdc++.h>
using namespace std;
long long n, t, a, b, c;
const int N = 200001;
const int B_MAX = 500000;
const long long inf = 1e15;
vector<pair<int, int> >v[N];
long long mx[N][4];
pair<long long, int> tmp_mx[4][2];
bool w[N];
priority_queue<pair<long long, long long>> q[4];
set<int>s;
int bnum[4];
int b_op;

void back(int i) {
  for (int j = 0; j < 2; j++) {
    if (tmp_mx[i][0].second != -1) {
      q[i].push(tmp_mx[i][0]);
    }
  }
}

long long h(int p, int pp, int z) {
  for (int i = 0; i < 4; i++) {
    while(!q[i].empty()) {q[i].pop();}
  }
  s.clear();

  for (int i = 0; i < v[p].size(); i++) {
    int a = v[p][i].first;
    if (a != pp && a != z) {
      long long c = v[p][i].second;
      q[0].push(make_pair(c, a));
      q[1].push(make_pair(mx[a][1] - mx[a][0] + c, a));
      q[2].push(make_pair(mx[a][2] - mx[a][0] + c, a));
      q[3].push(make_pair(mx[a][3] - mx[a][0] + c, a));
    }
  }

  long long res = 0;

  while (true) {
    for (int i = 0; i < 4; i++) {
      for (int j = 0; j < 2; j++) {
        while(!q[i].empty() && (s.find(q[i].top().second) != s.end() || q[i].top().second == -1)) {
          q[i].pop();
        }
        if (!q[i].empty()) {
          tmp_mx[i][j] = q[i].top();
          q[i].pop();
        } else {
          tmp_mx[i][j] = make_pair(-inf, -1);
        }
      }
    }

    long long mx11 = 0;
    if (tmp_mx[1][0].second != tmp_mx[1][1].second && tmp_mx[1][1].second != -1) {
      mx11 = tmp_mx[1][0].first + tmp_mx[1][1].first;
    }

    long long mx02 = 0;
    int a0 = -1, a2 = -1;
    if (tmp_mx[0][0].second != -1 && tmp_mx[2][0].second != -1) {
      if (tmp_mx[0][0].second != tmp_mx[2][0].second) {
        mx02 = tmp_mx[0][0].first + tmp_mx[2][0].first;
        a0 = 0;
        a2 = 0;
      }
      if (tmp_mx[0][1].second != -1 && tmp_mx[0][1].first + tmp_mx[2][0].first > mx02) {
        mx02 = tmp_mx[0][1].first + tmp_mx[2][0].first;
        a0 = 1;
        a2 = 0;
      }
      if (tmp_mx[2][1].second != -1 && tmp_mx[0][0].first + tmp_mx[2][1].first > mx02) {
        mx02 = tmp_mx[0][0].first + tmp_mx[2][1].first;
        a0 = 0;
        a2 = 1;
      }
    }

    long long mx33 = max(0LL, tmp_mx[3][0].first) + max(0LL, tmp_mx[3][1].first);

    if (mx02 <= 0 && mx11 <= 0 && mx33 <= 0) {
      return res;
    }

    if (mx02 > mx11 && mx02 > mx33) {
      res += mx02;
      s.insert(tmp_mx[0][a0].second);
      s.insert(tmp_mx[2][a2].second);
      q[0].push(tmp_mx[0][(a0 + 1) % 2]);
      q[2].push(tmp_mx[2][(a2 + 1) % 2]);
      back(1);
      back(3);
    } else if (mx11 > mx33) {
      res += mx11;
      s.insert(tmp_mx[1][0].second);
      s.insert(tmp_mx[1][1].second);
      back(0);
      back(2);
      back(3);
    } else {
      res += mx33;
      s.insert(tmp_mx[3][0].second);
      s.insert(tmp_mx[3][1].second);
      back(0);
      back(1);
      back(2);
    }
  }
  return res;
}

long long br(int p, int pp, int i, int z) {
  if (i == v[p].size()) {
    if (bnum[0] == bnum[2] && (bnum[1] % 2) == 0) {
      return 0;
    }
    return -inf;
  }

  long long a = v[p][i].first;
  long long res = br(p, pp, i + 1, z);

  if (a != pp && a != z) {
    long long c = v[p][i].second;
    bnum[0]++;
    res = max(res, c + br(p, pp, i + 1, z));
    bnum[0]--;

    for (int j = 1; j < 4; j++) {
      bnum[j]++;
      res = max(res, c + mx[a][j] - mx[a][0] + br(p, pp, i + 1, z));
      bnum[j]--;
    }
  }

  return res;
}

void r(int p, int pp) {
  for (int i = 0; i < v[p].size(); i++) {
    int a = v[p][i].first;
    if (a != pp) {
      r(a, p);
      mx[p][0] += mx[a][0];
    }
  }

  long long child_sum = mx[p][0];

  int kr = v[p].size() - 1;
  long long kr5 = (kr > 3 && kr < 9) ? pow(5, kr) : B_MAX;
  if (kr5 + b_op < B_MAX) {
    mx[p][0] += max(0LL, br(p, pp, 0, -1));
    b_op += kr5;
  } else {
    mx[p][0] += max(0LL, h(p, pp, -1));
  }

  for (int i = 0; i < v[p].size(); i++) {
    int a = v[p][i].first;
    if (a != pp) {
      long long c = v[p][i].second;
      long long bez = 0;
      if (kr5 + b_op < B_MAX) {
        bez = br(p, pp, 0, a);
        b_op += kr5;
      } else {
        bez = h(p, pp, a);
      }
      for (int j = 1; j < 4; j++) {
        mx[p][j] = max(mx[p][j], child_sum - mx[a][0] + bez + mx[a][j - 1] + c);
      }
    }
  }
}

void init(int a) {
  mx[a][0] = 0;
  mx[a][1] = -inf;
  mx[a][2] = -inf;
  mx[a][3] = -inf;
}

int main()
{
  ios_base::sync_with_stdio(0);

  cin >> n;
  init(0);

  for(int i = 1; i < n; i++) {
    init(i);
    cin >> a >> b >> c;
    a--;
    b--;
    v[a].push_back(make_pair(b, c));
    v[b].push_back(make_pair(a, c));
  }

  r(0, -1);

  cout << mx[0][0] << endl;

  return 0;
}