#include <bits/stdc++.h>
using namespace std;

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n, k;
  cin >> n >> k;
  vector<vector<int>> g(n);
  map<pair<int, int>, int> col;
  for (int _ = n - 1; _--; ) {
    int u, v, c;
    cin >> u >> v >> c;
    --u, --v, --c;
    g[u].push_back(v);
    g[v].push_back(u);
    col[{u, v}] = col[{v, u}] = c;
  }
  vector<bool> be(n, true);
  vector<int> sz(n), par(n);
  auto centroid = [&](int r) {
    vector<int> vs;
    auto dfs = [&](auto&& self, int v, int p) -> void {
      vs.push_back(v);
      par[v] = p;
      sz[v] = 1;
      for (int u : g[v]) {
        if (be[u] and u != p) {
          self(self, u, v);
          sz[v] += sz[u];
        }
      }
    };
    dfs(dfs, r, -1);
    for (int v : vs) {
      bool ok = vs.size() - sz[v] <= vs.size() / 2;
      for (int u : g[v]) {
        if (be[u] and u != par[v]) {
          if (sz[u] > (int)vs.size() / 2) {
            ok = false;
            break;
          }
        }
      }
      if (ok) {
        return v;
      }
    }
    return -1;
  };
  long long res = 0;
  map<int, int> mp1;
  map<pair<int, int>, int> mp2;
  auto dfs = [&](auto&& self, int v, int p, set<int> se) -> void {
    if (se.size() == 1) {
      ++mp1[*begin(se)];
    } else if (se.size() == 2) {
      ++mp2[{*begin(se), *next(begin(se))}];
    } else {
      assert(false);
    }
    for (int u : g[v]) {
      if (be[u] and u != p) {
        auto nse = se;
        nse.insert(col[{v, u}]);
        if (nse.size() >= 3) {
          continue;
        }
        self(self, u, v, nse);
      }
    }
  };
  auto rec = [&](auto&& self, int c) -> void {
    c = centroid(c);
    map<int, int> smp1;
    map<pair<int, int>, int> smp2;
    for (int v : g[c]) {
      if (be[v]) {
        mp1.clear(), mp2.clear();
        dfs(dfs, v, c, {col[{c, v}]});
        long long s1 = 0;
        for (auto e : mp1) {
          res += (long long)e.second * e.second;
          s1 += e.second;
        }
        res -= s1 * s1;
        for (auto e : mp2) {
          res += 2 * e.second;
          res -= 2 * (long long)((mp1.count(e.first.first) ? mp1[e.first.first] : 0) + (mp1.count(e.first.second) ? mp1[e.first.second] : 0)) * e.second;
          res -= (long long)e.second * e.second;
        }
        for (auto e : mp1) {
          smp1[e.first] += e.second;
        }
        for (auto e : mp2) {
          smp2[e.first] += e.second;
        }
      }
    }
    long long s1 = 0;
    for (auto e : smp1) {
      res -= (long long)e.second * e.second;
      s1 += e.second;
    }
    res += s1 * s1;
    for (auto e : smp2) {
      res += 2 * (long long)((smp1.count(e.first.first) ? smp1[e.first.first] : 0) + (smp1.count(e.first.second) ? smp1[e.first.second] : 0)) * e.second;
      res += (long long)e.second * e.second;
    }
    be[c] = false;
    for (int u : g[c]) {
      if (be[u]) {
        self(self, u);
      }
    }
    be[c] = true;
  };
  rec(rec, 0);
  res /= 2;
  cout << res << '\n';
}