#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){
while(a > 0 && b > 0){
if (a > b) a %= b;
else b %= a;
}
return a + b;
}
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return __lg(mask);}
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
template <class T1, class T2>
bool maximize(T1 &a, T2 b){
if (a < b) {a = b; return true;}
return false;
}
template <class T1, class T2>
bool minimize(T1 &a, T2 b){
if (a > b) {a = b; return true;}
return false;
}
template <class T>
void printArr(T& container, string separator = " ", string finish = "\n"){
for(auto item: container) cout << item << separator;
cout << finish;
}
template <class T>
void remove_dup(vector<T> &a){
sort(ALL(a));
a.resize(unique(ALL(a)) - a.begin());
}
struct FenwickTree{
int n;
vector<ll> a;
FenwickTree(int _n){
n = _n;
a.resize(n+1);
}
void update(int i, ll v){
while(i <= n){
a[i] += v;
i += LASTBIT(i);
}
}
ll get(int i){
ll ans = 0;
while(i > 0){
ans += a[i];
i -= LASTBIT(i);
}
return ans;
}
ll get(int l, int r){return get(r) - get(l-1);}
int binary_lift(ll x){
int p = MASK(logOf(n)), idx =0;
while(p > 0){
if (idx + p <= n && x > a[idx + p]){
idx += p;
x -= a[idx];
}
p >>= 1;
}
return idx + 1;
}
};
const int N = 1e5 + 69;
int n, k;
vector<pair<int, int>> graph[N];
int weight[N];
ll ans = 0;
ll count_pair(vector<pair<int, int>> a){
if (a.size() == 1) return 0;
int ma = 0;
for(pair<int, int> i: a) maximize(ma, i.second);
FenwickTree bit(ma + 1);
sort(ALL(a));
ll ans = 0;
for(pair<int, int> i: a){
int cur = i.first - k - i.second;
if (cur >= 0) ans += bit.get(min(cur + 1, ma + 1));
bit.update(i.second + 1, 1);
}
return ans;
}
namespace CentroidDecomposition{
bool banned[N];
int sz[N];
int h[N], ma[N];
void find_sz(int u, int p){
sz[u] = 1;
for(pair<int, int> v: graph[u]) if (v.first != p && !banned[v.second]){
find_sz(v.first, u);
sz[u] += sz[v.first];
}
}
int find_centroid(int u){
for(pair<int, int> v: graph[u]) if (!banned[v.second]) {
if (sz[v.first] * 2 > sz[u]) {
sz[u] -= sz[v.first];
sz[v.first] += sz[u];
return find_centroid(v.first);
}
}
return u;
}
void dfs(int u, int p){
for(pair<int, int> v: graph[u]) if (v.first != p && !banned[v.second]){
h[v.first] = h[u] + 1;
ma[v.first] = max(ma[u], weight[v.second]);
dfs(v.first, u);
}
}
void get_point(int u, int p, vector<pair<int, int>> &skr){
skr.push_back({ma[u], h[u]});
for(pair<int, int> v: graph[u]) if (v.first != p && !banned[v.second]){
get_point(v.first, u, skr);
}
}
void go(int u, int layer){
find_sz(u, 0);
u = find_centroid(u);
h[u] = 0, ma[u] = 0;
dfs(u, 0);
vector<vector<pair<int, int>>> ski;
vector<pair<int, int>> tot;
tot.push_back({0, 0});
for(pair<int, int> v: graph[u]) if (!banned[v.second]){
vector<pair<int, int>> skr;
get_point(v.first, u, skr);
for(pair<int, int> j: skr) tot.push_back(j);
ski.push_back(skr);
}
// cout << "->> Node: " << u << "\n";
// for(pair<int, int> j: tot) cout << j.first << " " << j.second << "\n";
// cout << "Plus: " << count_pair(tot) << "\n";
ans += count_pair(tot);
for(auto j: ski){
ans -= count_pair(j);
}
for(pair<int, int> v: graph[u]) if (!banned[v.second]){
banned[v.second] = true;
go(v.first, layer + 1);
}
}
}
void solve(){
cin >> n >> k;
for(int i = 1; i < n; ++i){
int u, v; cin >> u >> v >> weight[i];
graph[u].push_back({v, i});
graph[v].push_back({u, i});
}
CentroidDecomposition::go(1, 0);
cout << ans * 2 << "\n";
}
int main(void){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
clock_t start = clock();
solve();
cerr << "Time elapsed: " << clock() - start << "ms!\n";
return 0;
}
