#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int>P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);
//typedef vector<vector<ll>> mat;
typedef vector<int> vec;

ll mod_pow(ll a, ll n, ll m) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * a%m;
		a = a * a%m; n >>= 1;
	}
	return res;
}

struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n%mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint &a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint &a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint &a, modint b) { a.n = ((ll)a.n*b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
	if (n == 0)return modint(1);
	modint res = (a*a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p%a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 18;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}
using mP = pair<modint, modint>;

int dx[4] = { 0,1,0,-1 };
int dy[4] = { 1,0,-1,0 };

typedef modint Data;
typedef vector<Data> Array;
typedef vector<Array> mat;
mat operator*(const mat &lhs, const mat &rhs) {
	mat ret(lhs.size(), Array(rhs[0].size(), 0));
	rep(i, lhs.size())rep(j, rhs[0].size())rep(k, rhs.size()) {
		ret[i][j] = lhs[i][k]*rhs[k][j]+ret[i][j];
	}
	return ret;
}
mat scalar(int sz, Data k) {
	mat ret(sz, Array(sz, 0));
	rep(i, sz)ret[i][i] = k;
	return ret;
}
mat operator^(const mat &lhs, const ll n) {
	if (n == 0)return scalar(lhs.size(), 1);
	mat ret = (lhs*lhs) ^ (n / 2);
	if (n % 2) {
		ret = ret * lhs;
	}
	return ret;
}

const int mn = 1 << 18;
struct edge {
	int to, col;
};
vector<edge> G[mn];
queue<vector<int>> q;
bool exi[mn];

ll ans = 0;
void yaru(vector<int> v) {
	if (v.empty())return;
	//初期化
	for (int id : v)exi[id] = true;
	int g; int sz = v.size();

	function<int(int, int)> s_root = [&](int id, int fr)->int {
		int res = 1;
		int ma = 0;
		for (edge e : G[id]) {
			int to = e.to;
			if (to == fr)continue;
			if (!exi[to])continue;
			int nex = s_root(to, id);
			ma = max(ma, nex);
			res += nex;
		}
		if (ma <= sz / 2 && sz - res <= sz / 2)g = id;
		return res;
	};
	s_root(v[0], -1);
	//ここまで初期化

	map<P, int> alcnt;
	map<P, int> subcnt;
	ll c1 = 0;
	ll subc1 = 0;
	//重心を根としてなんかやる
	function<void(int, int,P)> dfs = [&](int id, int fr,P cols) {
		if (!exi[id])return;
		alcnt[cols]++;
		subcnt[cols]++;
		if (cols.first < 0) {
			c1++; subc1++;
		}
		for (edge e : G[id]) {
			int to = e.to;
			if (to == fr)continue;
			P nex = cols;
			if (e.col == nex.first || e.col == nex.second) {
				//
			}
			else if (nex.first == -1) {
				nex.first = e.col;
				if (nex.first > nex.second)swap(nex.first, nex.second);
			}
			else continue;
			dfs(to, id, nex);
		}
	};
	//cout << "root is " << g << endl;
	//cout << "start" << endl;
	ll csum = 0;
	for (edge e : G[g]) {
		subcnt.clear();
		subc1 = 0;
		P ori = { -1,e.col };
		dfs(e.to, g,ori);
		for (pair<P, int> p : subcnt) {
			P cur = p.first;
			ll num = p.second;
			if(cur.first>=0){
				csum -= num*subcnt[cur];
				csum -= 2*num*subcnt[{-1, cur.first}];
				csum -= 2*num*subcnt[{-1, cur.second}];
			}
		}
		csum -= subc1 * subc1;
		//cout << e.to << " ! " << csum << endl;
	}
	ll gcnt = 0;
	for (pair<P, int> p : alcnt) {
		P cur = p.first;
		ll num = p.second;
		gcnt += num;
		if (cur.first >= 0) {
			csum += num*alcnt[cur];
			csum += 2*num*alcnt[{-1, cur.first}];
			csum += 2*num*alcnt[{-1, cur.second}];
		}
	}
	csum += c1 * c1;
	ans += csum;

	ans += 2*gcnt;

	//cout << csum <<" ?? "<<gcnt<< endl;
	//cout << "end" << endl;
	//ここまで

	vector<vector<int>> chs;
	vector<int> nexs;
	function<void(int, int)> search_next = [&](int id, int fr) {
		if (!exi[id])return;
		nexs.push_back(id);
		for (edge e : G[id]) {
			int to = e.to;
			if (to == fr)continue;
			search_next(to, id);
		}
	};
	//子を列挙する
	for (edge e : G[g]) {
		int to = e.to;
		search_next(to, g);
		if (nexs.empty())continue;
		q.push(nexs);
		chs.push_back(nexs);
		nexs.clear();
	}

	//子達についてなんかやる



	for (int id : v)exi[id] = false;
}

void uoo(int n) {
	vector<int> ori(n); rep(i, n)ori[i] = i;
	q.push(ori);
	while (!q.empty()) {
		vector<int> v = q.front(); q.pop();
		yaru(v);
	}
}

struct uf {
private:
	vector<int> par, ran,sz;
public:
	uf(int n) {
		par.resize(n, 0);
		ran.resize(n, 0);
		sz.resize(n, 1);
		rep(i, n) {
			par[i] = i;
		}
	}
	int find(int x) {
		if (par[x] == x)return x;
		else return par[x] = find(par[x]);
	}
	void unite(int x, int y) {
		x = find(x), y = find(y);
		if (x == y)return;
		if (ran[x] < ran[y]) {
			par[x] = y; sz[y] += sz[x];
		}
		else {
			par[y] = x; sz[x] += sz[y];
			if (ran[x] == ran[y])ran[x]++;
		}
	}
	bool same(int x, int y) {
		return find(x) == find(y);
	}
	int comp(int x) { return sz[x]; }
};

vector<P> vs[1 << 18];
void solve() {
	int n, k; cin >> n >> k;
	rep(i, n - 1) {
		int a, b, c; cin >> a >> b >> c; a--; b--;
		G[a].push_back({ b,c });
		G[b].push_back({ a,c });
		vs[c].push_back({ a,b });
	}
	uoo(n);

	ll num1 = 0;
	rep1(i, k) {
		if (vs[i].size() == 0)continue;
		vector<int> ids;
		for (P p : vs[i]) {
			ids.push_back(p.first);
			ids.push_back(p.second);
		}
		sort(all(ids));
		ids.erase(unique(all(ids)), ids.end());
		map<int, int> trans;
		rep(j, ids.size())trans[ids[j]] = j;
		rep(j, vs[i].size()) {
			vs[i][j].first = trans[vs[i][j].first];
			vs[i][j].second = trans[vs[i][j].second];
		}
		uf u(trans.size());
		for (P p : vs[i]) {
			u.unite(p.first, p.second);
		}
		vector<bool> used(trans.size(), false);
		rep(j, trans.size()) {
			int p = u.find(j);
			if (used[p])continue;
			used[p] = true;
			ll sz = u.comp(p);
			num1 += sz * (sz - 1);
		}
	}

	//cout << num1 << endl;
	ans -= num1;
	cout << ans/2 << endl;
}


signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(10);
	init_f();
	//init();
	//int t; cin >> t; rep(i, t)solve();
	solve();
	stop
		return 0;
}