#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), col(n);
  for (int _ = n - 1; _--; ) {
    int u, v, c;
    cin >> u >> v >> c;
    --u, --v;
    g[u].push_back(v), col[u].push_back(c);
    g[v].push_back(u), col[v].push_back(c);
  }
  vector<bool> be(n, true);
  vector<int> sz(n), par(n);
  auto centroids = [&](int r, int cur_n) {
    vector<int> res;
    auto dfs = [&](auto&& self, int v, int p) -> void {
      sz[v] = 1, par[v] = p;
      bool ok = true;
      for (int u : g[v]) {
        if (be[u] and u != p) {
          self(self, u, v);
          sz[v] += sz[u];
          ok &= 2 * sz[u] <= cur_n;
        }
      }
      if (ok and 2 * sz[v] >= cur_n) {
        res.push_back(v);
      }
    };
    dfs(dfs, r, -1);
    return res;
  };
  vector<int> c1;
  vector<pair<int, int>> c2;
  auto dfs = [&](auto&& self, int v, int p, const vector<int>& cs) -> void {
    if (cs.size() == 1) {
      c1.push_back(cs[0]);
    } else {
      c2.emplace_back(cs[0], cs[1]);
    }
    for (int id = 0; id < (int)g[v].size(); ++id) {
      int u = g[v][id], c = col[v][id];
      if (be[u] and u != p) {
        if (cs.size() == 1) {
          if (c < cs[0]) {
            self(self, u, v, {c, cs[0]});
          } else if (cs[0] < c) {
            self(self, u, v, {cs[0], c});
          } else {
            self(self, u, v, cs);
          }
        } else if (c == cs[0] or c == cs[1]) {
          self(self, u, v, cs);
        }
      }
    }
  };
  auto f11 = [&](int s, int t) {
    long long res = 0;
    for (int l = s, r = s; l < t; ++l) {
      while (r < t and c1[r] <= c1[l]) {
        ++r;
      }
      res += t - r;
    }
    return res;
  };
  auto f12 = [&](int s1, int t1, int s2, int t2) {
    vector<int> cs(2 * (t2 - s2));
    for (int i = 0; i < (int)cs.size(); i += 2) {
      tie(cs[i], cs[i + 1]) = c2[s2 + i / 2];
    }
    sort(begin(cs), end(cs));
    long long res = 0;
    int l = s1, r = s1;
    for (int e : cs) {
      while (l < t1 and c1[l] < e) {
        ++l;
      }
      while (r < t1 and c1[r] <= e) {
        ++r;
      }
      res += r - l;
    }
    return res;
  };
  auto f22 = [&](int s, int t) {
    long long res = 0;
    for (int l = s, r = s; l < t; ++l) {
      while (r < t and c2[r] <= c2[l]) {
        ++r;
      }
      res += r - l - 1;
    }
    return res;
  };
  long long res = 0;
  auto rec = [&](auto&& self, int c, int cur_n) -> void {
    c = centroids(c, cur_n)[0];
    be[c] = false;
    for (int v : g[c]) {
      if (be[v]) {
        self(self, v, par[v] == c ? sz[v] : cur_n - sz[c]);
      }
    }
    be[c] = true;
    c1.clear(), c2.clear();
    for (int id = 0; id < (int)g[c].size(); ++id) {
      int v = g[c][id];
      if (be[v]) {
        int n1 = c1.size(), n2 = c2.size();
        dfs(dfs, v, c, {col[c][id]});
        sort(begin(c1) + n1, end(c1));
        sort(begin(c2) + n2, end(c2));
        res -= f12(n1, c1.size(), n2, c2.size());
        res -= f22(n2, c2.size());
      }
    }
    sort(begin(c1), end(c1));
    sort(begin(c2), end(c2));
    int n1 = c1.size(), n2 = c2.size();
    res += c2.size();
    res += f11(0, n1);
    res += f12(0, n1, 0, n2);
    res += f22(0, n2);
  };
  rec(rec, 0, n);
  cout << res << '\n';
}