#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10;
long long siz[2][N], par[2][N];
int get(int u, int w) {
  if (par[w][u] == u) return u;
  return par[w][u] = get(par[w][u], w);
}
void merge(int u, int v, int w) {
  int x = get(u, w);
  int y = get(v, w);
  if (siz[w][x] < siz[w][y]) {
    swap(x, y);
  }
  par[w][y] = x;
  siz[w][x] += siz[w][y];
}
void nikal_pehli_fursat_mai() {
  int n;
  cin >> n;
  for (int i = 1; i < n + 1; i++) {
    siz[0][i] = siz[1][i] = 1;
    par[0][i] = par[1][i] = i;
  }
  for (int i = 0; i < n - 1; i++) {
    int u, v, w;
    cin >> u >> v >> w;
    merge(u, v, w);
  }
  long long ans = 0;
  for (int i = 1; i < n + 1; i++) {
    if (par[0][i] == i) {
      ans += (siz[0][i] * siz[0][i] - siz[0][i]);
    }
    if (par[1][i] == i) {
      ans += (siz[1][i] * siz[1][i] - siz[1][i]);
    }
    ans += (siz[0][get(i, 0)] - 1) * (siz[1][get(i, 1)] - 1);
  }
  cout << ans << "\n";
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int tc = 1;
  while (tc--) {
    nikal_pehli_fursat_mai();
  }
}
