#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int DY[]{1, 0, -1, 0}, DX[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}, DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

template <typename CostType>
struct Edge {
  int src, dst; CostType cost;
  Edge(int src, int dst, CostType cost = 0) : src(src), dst(dst), cost(cost) {}
  inline bool operator<(const Edge &x) const {
    return cost != x.cost ? cost < x.cost : dst != x.dst ? dst < x.dst : src < x.src;
  }
  inline bool operator<=(const Edge &x) const { return !(x < *this); }
  inline bool operator>(const Edge &x) const { return x < *this; }
  inline bool operator>=(const Edge &x) const { return !(*this < x); }
};

int main() {
  int n; cin >> n;
  vector<vector<Edge<int>>> graph(n);
  REP(_, n - 1) {
    int a, b, c; cin >> a >> b >> c; --a; --b;
    graph[a].emplace_back(a, b, c);
    graph[b].emplace_back(b, a, c);
  }
  ll ans = n * (n - 1LL);
  vector<int> x(n, 0), y(n, 0), subtree(n, 1);
  const auto f = [&](auto&& f, int par, int ver) -> map<int, pair<ll, int>> {
    map<int, pair<ll, int>> y_cnt;
    for (const Edge<int>& e : graph[ver]) {
      if (e.dst == par) continue;
      x[e.dst] = x[ver] ^ e.cost;
      map<int, pair<ll, int>> child = f(f, ver, e.dst);
      subtree[ver] += subtree[e.dst];
      if (child.count(x[ver]) == 1) {
        ans -= child[x[ver]].first;
        ans -= 1LL * child[x[ver]].second * (n - subtree[e.dst]);
      }
      if (y_cnt.size() < child.size()) swap(y_cnt, child);
      for (const auto [x_i, sum_cnt] : child) {
        if (x_i != x[ver] && y_cnt.count(x_i) == 1) {
          ans -= 1LL * y_cnt[x_i].second * sum_cnt.first;
          ans -= 1LL * y_cnt[x_i].first * sum_cnt.second;
        }
      }
      for (const auto [x_i, sum_cnt] : child) {
        y_cnt[x_i].first += sum_cnt.first;
        y_cnt[x_i].second += sum_cnt.second;
      }
    }
    y[ver] = subtree[ver] - y_cnt[x[ver]].first;
    y_cnt[x[ver]].first += y[ver];
    y_cnt[x[ver]].second = 1;
    return y_cnt;
  };
  f(f, -1, 0);
  // REP(i, n) cerr << x[i] << " \n"[i + 1 == n];
  // REP(i, n) cerr << y[i] << " \n"[i + 1 == n];
  cout << ans << '\n';
  return 0;
}