#define taskname ""
#include <bits/stdc++.h>
using namespace std;
const int kMaxNW = 100005;
struct FenwickTree {
int x;
vector<int> bit;
FenwickTree(int _x) : x(_x) {
bit.resize(x + 2, 0);
}
void Update(int p, int d) {
p++;
for (int i = p; i <= x; i += i & (-i)) {
bit[i] += d;
}
}
int PrefixSum(int p) {
p++;
int s = 0;
for (int i = p; i > 0; i -= i & (-i)) {
s += bit[i];
}
return s;
}
};
int n, k, sz[kMaxNW];
long long cnt;
bool deleted[kMaxNW];
vector<pair<int, int>> adj[kMaxNW];
FenwickTree a(kMaxNW);
int DFS1(int u, int p) {
sz[u] = 1;
for (auto i : adj[u]) {
int v = i.first;
if (v == p || deleted[v]) {
continue;
}
DFS1(v, u);
sz[u] += sz[v];
}
return sz[u];
}
int FindCentroid(int u, int p, int m) {
for (auto i : adj[u]) {
int v = i.first;
if (v == p || deleted[v]) {
continue;
}
if (sz[v] > m / 2) {
return FindCentroid(v, u, m);
}
}
return u;
}
struct T {
int v, d, mw;
};
void DFS2(int u, int p, int depth, int max_weight, vector<T>& S) {
S.push_back({u, depth, max_weight});
for (auto i : adj[u]) {
int v = i.first, w = i.second;
if (v == p || deleted[v]) {
continue;
}
DFS2(v, u, depth + 1, max(max_weight, w), S);
}
}
void CentroidDecomposition(int u) {
int g = DFS1(u, -1), c = FindCentroid(u, -1, g);
deleted[c] = true;
vector<T> S;
DFS2(c, -1, 0, 0, S);
sort(S.begin(), S.end(), [](T x, T y) {
return x.mw < y.mw;
});
for (int i = 0; i < S.size(); i++) {
if (S[i].mw - S[i].d - k >= 0) {
cnt += a.PrefixSum(S[i].mw - S[i].d - k);
}
a.Update(S[i].d, 1);
}
for (int i = 0; i < S.size(); i++) {
a.Update(S[i].d, -1);
}
for (auto i : adj[c]) {
int v = i.first, w = i.second;
if (deleted[v]) {
continue;
}
vector<T> M;
DFS2(v, c, 1, w, M);
sort(M.begin(), M.end(), [](T x, T y) {
return x.mw < y.mw;
});
for (int i = 0; i < M.size(); i++) {
if (M[i].mw - M[i].d - k >= 0) {
cnt -= a.PrefixSum(M[i].mw - M[i].d - k);
}
a.Update(M[i].d, 1);
}
for (int i = 0; i < M.size(); i++) {
a.Update(M[i].d, -1);
}
}
for (auto i : adj[c]) {
int v = i.first;
if (deleted[v]) {
continue;
}
CentroidDecomposition(v);
}
}
int main() {
if (fopen(taskname".inp", "r")) {
freopen(taskname".inp", "r", stdin);
freopen(taskname".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> k;
for (int i = 1; i < n; i++) {
int x, y, w;
cin >> x >> y >> w;
adj[x].push_back({y, w});
adj[y].push_back({x, w});
}
int root = 1;
CentroidDecomposition(root);
cout << 2 * cnt;
return 0;
}
