#include <bits/stdc++.h>
// #define MULTI_TEST_CASE
// #define TEST_TEXT
using namespace std;
#define ll long long
#define MAX(a, b) (a) = max((a), (b))
#define MIN(a, b) (a) = min((a), (b))
#define all(a) (a).begin(), (a).end()
#define sortedpair(a, b) {min((a), (b)), max((a), (b))}
const ll MOD = 1e9+7;
struct edge {
int to, w;
};
int n, k;
vector<vector<edge>> v;
ll ans = 0;
vector<bool> voltcentroid;
vector<int> siz;
const int st_size = 200001;
vector<ll> st;
void add(int d, int diff = 1) {
d += st_size;
st[d] += diff;
for (d /= 2; d >= 1; d /= 2) {
st[d] = st[2*d] + st[2*d+1];
}
}
ll query(int l, int r) {
l += st_size; r += st_size;
ll res = 0;
while (l <= r) {
if (l % 2 == 1) res += st[l++];
if (r % 2 == 0) res += st[r--];
l /= 2; r /= 2;
}
return res;
}
// void add(vector<ll> &st, int d, int dif = 1, int ind = 1, int l = 0, int r = st_size-1){
// if(l == r){
// st[ind]+=dif;
// return;
// }
// int mid = (l+r)/2;
// if(d <= mid) add(st, d, dif, ind*2, l, mid);
// else add(st, d, dif, ind*2+1, mid+1, r);
// st[ind] = st[ind*2] + st[ind*2+1];
// }
// ll query(vector<ll> &st, int ql, int qr, int ind = 1, int l = 0, int r = st_size-1){
// if(qr < ql)return 0;
// if(r < ql || l > qr)return 0;
// if(ql <= l && r <= qr) return st[ind];
// int mid = (l+r)/2;
// return query(st, ql, qr, ind*2, l, mid) + query(st, ql, qr, ind*2+1, mid+1, r);
// }
int c_szamoz(int x, int p = -1){
siz[x] = 1;
for(edge&i : v[x]){
if(i.to != p && !voltcentroid[i.to])
siz[x] += c_szamoz(i.to, x);
}
return siz[x];
}
int c_keres(int x, int meret, int p = -1){
for(edge&i : v[x]){
if(i.to != p && !voltcentroid[i.to]){
if(siz[i.to] > meret/2){
return c_keres(i.to, meret, x);
}
}
}
return x;
}
struct c_ut {
int w, x, d;
bool operator<(const c_ut & other) const {
return -w < -other.w;
}
};
vector<int> inserts;
void reset_st(){
while(inserts.size()){
add(inserts.back(), -1);
inserts.pop_back();
}
}
void megold(int x = 0){
int meret = c_szamoz(x);
int centroid = c_keres(x, meret);
// st_ut_max.assign(st_size*2, 0);
add(0, 1); inserts.push_back(0);
vector<bool> seen(n, 0);
seen[centroid] = 1;
priority_queue<c_ut> q;
for(edge&i : v[centroid]){
if(!voltcentroid[i.to]){
q.push({i.w, i.to, 1});
}
}
while(!q.empty()){
c_ut c = q.top();
q.pop();
seen[c.x] = 1;
ans += query(0, c.w-c.d-k);
add(c.d, 1); inserts.push_back(c.d);
for(edge&i : v[c.x]){
if(!seen[i.to] && !voltcentroid[i.to]){
q.push({max(c.w, i.w), i.to, c.d+1});
}
}
}
reset_st();
seen.assign(n, 0);
for(edge&i : v[centroid]){
if(!voltcentroid[i.to]){
seen[centroid] = 1;
priority_queue<c_ut> q;
q.push({i.w, i.to, 1});
while(!q.empty()){
c_ut c = q.top();
q.pop();
if(seen[c.x])continue;
seen[c.x] = 1;
ans -= query(0, c.w-c.d-k);
add(c.d, 1); inserts.push_back(c.d);
for(edge&i : v[c.x]){
if(!seen[i.to] && !voltcentroid[i.to]){
q.push({max(c.w, i.w), i.to, c.d+1});
}
}
}
reset_st();
}
}
// add(st_ut, 0);
// for(edge&i : v[centroid]){
// if(!voltcentroid[i.to]){
// c_szamol(i.to, i.w, 1, centroid);
// c_frissit(i.to, i.w, 1, centroid);
// }
// }
voltcentroid[centroid] = true;
for(edge&i : v[centroid]){
if(!voltcentroid[i.to]){
megold(i.to);
}
}
}
void solve(){
cin>>n>>k;
v.assign(n, {});
voltcentroid.assign(n, 0);
st.assign(2*st_size, 0);
siz.assign(n, 0);
for(int i = 0; i < n-1; i++){
int a, b, c; cin>>a>>b>>c; a--; b--;
v[a].push_back({b, c});
v[b].push_back({a, c});
}
megold();
cout<<ans*2<<endl;
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
int _t = 1;
#ifdef MULTI_TEST_CASE
cin >> _t;
#endif
for(int _i = 0; _i < _t; _i++){
#ifdef TEST_TEXT
cout<<"Case #"<<_i+1<<": ";
#endif
solve();
}
return 0;
}
