#include <bits/stdc++.h>
#pragma comment(linker, "/stack:247474112")
#pragma GCC optimize("Ofast")
using namespace std;
const long long LLINF = 0x3f3f3f3f3f3f3f3f;
const int INF = 0x3f3f3f3f;
void accelerate() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
}
const int MAXN = 2e5 + 10;
long long dp[MAXN][4];
long long ans;
int n;
vector<int> E[MAXN];
map<pair<int, int>, int> C;
void DFS(int v = 0, int fa = -1) {
  for (auto u : E[v]) {
    if (u != fa) {
      DFS(u, v);
      if (C[make_pair(min(u, v), max(u, v))] == 0) {
        dp[v][0] += dp[u][0] + 1;
        dp[v][2] += dp[u][2] + dp[u][1];
      } else {
        dp[v][1] += dp[u][1] + 1;
        dp[v][3] += dp[u][3] + dp[u][0];
      }
    }
  }
  ans += 2 * dp[v][0] + 2 * dp[v][1] + dp[v][2] + dp[v][3];
  for (auto u : E[v]) {
    if (u != fa) {
      if (C[make_pair(min(u, v), max(u, v))] == 0) {
        ans += (dp[u][0] + 1) * (dp[v][0] - dp[u][0] - 1);
        ans += (dp[u][0] + 1) * (dp[v][2] - (dp[u][2] + dp[u][1]) + dp[v][1]);
      } else {
        ans += (dp[u][1] + 1) * (dp[v][1] - dp[u][1] - 1);
        ans += (dp[u][0] + dp[u][3]) * (dp[v][1] - dp[u][1] - 1);
      }
    }
  }
}
int main() {
  accelerate();
  cin >> n;
  for (int i = 0; i < n - 1; ++i) {
    int x, y;
    cin >> x >> y;
    --x, --y;
    E[x].push_back(y);
    E[y].push_back(x);
    cin >> C[make_pair(min(x, y), max(x, y))];
  }
  DFS();
  cout << ans << endl;
}
