#include <bits/stdc++.h>
using namespace std;
vector<pair<int, int> > g[200100];
bool used[200100][2];
int pr[200100][2];
int cost[200100][2];
int dfs(int v, int type) {
  pr[v][type] = v;
  used[v][type] = 1;
  int ret = 1;
  for (int i = 0; i < g[v].size(); i++) {
    pair<int, int> to = g[v][i];
    if (to.second == type && !used[to.first][to.second]) {
      ret += dfs(to.first, to.second);
      pr[to.first][to.second] = v;
    }
  }
  return ret;
}
int get(int v, int type) {
  while (pr[v][type] != v) {
    pr[v][type] = pr[pr[v][type]][type];
    v = pr[v][type];
  }
  return cost[v][type];
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int n;
  cin >> n;
  long long ans = 0;
  for (int i = 1; i <= n - 1; i++) {
    int f, s, c;
    cin >> f >> s >> c;
    g[f].push_back(make_pair(s, c));
    g[s].push_back(make_pair(f, c));
  }
  for (int i = 1; i <= n; i++) {
    long long f, s;
    if (!used[i][1]) {
      s = dfs(i, 1);
      cost[i][1] = s;
    } else
      s = get(i, 1);
    if (!used[i][0]) {
      f = dfs(i, 0);
      cost[i][0] = f;
    } else
      f = get(i, 0);
    ans += (f - 1);
    ans += (s - 1);
    ans += (f - 1) * (s - 1);
  }
  cout << ans << endl;
  return 0;
}
