#include <bits/stdc++.h>
using namespace std;
void JIZZ(string output = "") {
  cout << output;
  exit(0);
}
const long double PI = 3.14159265358979323846264338327950288;
const long double eps = 1e-10;
const long long mod = 1e9 + 7;
int djs[2][200005], sz[2][200005];
int F(int i, int u) { return djs[i][u] == u ? u : djs[i][u] = F(i, djs[i][u]); }
void U(int i, int u, int v) {
  u = F(i, u);
  v = F(i, v);
  if (u == v) return;
  djs[i][v] = u;
  sz[i][u] += sz[i][v];
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    djs[0][i] = djs[1][i] = i;
    sz[0][i] = sz[1][i] = 1;
  }
  for (int i = 1; i < n; ++i) {
    int u, v, w;
    cin >> u >> v >> w;
    U(w, u, v);
  }
  long long ans = 0;
  for (int i = 1; i <= n; ++i) {
    ans += 1ll * (sz[0][F(0, i)] - 1) * (sz[1][F(1, i)] - 1) +
           (sz[0][F(0, i)] - 1) + (sz[1][F(1, i)] - 1);
  }
  cout << ans << endl;
}
