#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using T = tuple<ll, ll, ll>;
#define int long long
#define Base 41
#define sz(a) (int)a.size()
#define FOR(i, a, b) for ( int i = a ; i <= b ; i++ )
#define FORD(i, a, b) for (int i = b; i >= a; i --)
#define REP(i, n) for (int i = 0; i < n; ++i)
#define REPD(i, n) for (int i = n - 1; i >= 0; --i)
#define all(x) x.begin() , x.end()
#define pii pair<int , int>
#define fi first
#define se second
#define Lg(x) 31 - __builtin_clz(x)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int MAX = 2e5 + 5;
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
void setupIO(){
#define name "Whisper"
//Phu Trong from Nguyen Tat Thanh High School for gifted student
srand(time(NULL));
cin.tie(nullptr)->sync_with_stdio(false); cout.tie(nullptr);
//freopen(name".inp", "r", stdin);
//freopen(name".out", "w", stdout);
cout << fixed << setprecision(10);
}
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
int numNode, K;
vector<pii> adj[MAX];
int sz[MAX], del[MAX];
void reSubsize(int u, int p){
sz[u] = 1;
for (auto&[v, w] : adj[u]) if(v ^ p){
if (!del[v]){
reSubsize(v, u); sz[u] += sz[v];
}
}
}
int getCentroid(int u, int p, int siz){
for (auto&[v, w] : adj[u]) if(v ^ p){
if (sz[v] * 2 > siz && !del[v]) return getCentroid(v, u, siz);
}
return u;
}
//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
struct FenwickTree{
int n = 2 * MAX - 5;
int f[2 * MAX]{0};
vector<int> opt;
void modify(int p, int val){
if (val > 0) opt.push_back(p);
for (; p <= n; p += p & (-p)) f[p] += val;
}
int query(int p){
int res = 0;
for ( ; p > 0; p -= p & (-p)) res += f[p];
return res;
}
void clear(){
while (opt.size()){
int p = opt.back(); opt.pop_back();
modify(p, -1);
}
}
} fen;
int ans = 0;
vector<pii> subtree;
void dfs(int u, int p, int mxValue, int dep){
if (dep > 0)
subtree.emplace_back(mxValue, dep);
for (auto&[v, w] : adj[u]) if(v ^ p){
if (del[v]) continue;
int nxt = max(mxValue, w);
dfs(v, u, nxt, dep + 1);
}
}
void compute(int val, int ok){
sort(all(subtree));
for (auto&[w, l] : subtree){
int needL = w - K - l;
if (w - l >= K) ans += ok;
ans += fen.query(needL) * val;
fen.modify(l, 1);
}
for (auto&[w, l] : subtree){
fen.modify(l, -1);
}
subtree.clear();
}
void decompose(int root){
reSubsize(root, -1);
int siz = sz[root];
root = getCentroid(root, -1, siz);
dfs(root, -1, 0, 0);
compute(1, 1);
for (auto&[v, w] : adj[root]) if(!del[v]){
dfs(v, root, w, 1);
compute(-1, 0);
}
del[root] = 1;
for (auto&[v, w] : adj[root]) if (!del[v]){
decompose(v);
}
}
//count the number from (x -> y) that the difference of the max weight and the length of the path >= K
void Whisper(){
cin >> numNode >> K;
for (int i = 1; i < numNode; ++i){
int u, v, w; cin >> u >> v >> w;
adj[u].emplace_back(v, w);
adj[v].emplace_back(u, w);
}
decompose(1);
cout << ans * 2;
}
signed main(){
setupIO();
int Test = 1;
// cin >> Test;
for ( int i = 1 ; i <= Test ; i++ ){
Whisper();
if (i < Test) cout << '\n';
}
}
