#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9 + 7;
const ll LOGN = 18;
const ll MAXN = 1e5 + 100;
vector<vector<pair<int,int>>> graph;
int marked[MAXN], sz[MAXN], fen[MAXN], k;
ll ans = 0;
ll get(int k) {
k++;
if (k <= 0)
return 0;
ll res = 0;
while (k) {
res += fen[k];
k -= k & -k;
}
return res;
}
void update(int k, int v) {
k++;
while (k < MAXN) {
fen[k] += v;
k += k & -k;
}
}
int get_sz(int node, int parent) {
sz[node] = 1;
for (auto u : graph[node]) {
if (u.f == parent || marked[u.f])
continue;
sz[node] += get_sz(u.f, node);
}
return sz[node];
}
int find_centro(int node, int parent, int n) {
for (auto u : graph[node]) {
if (u.f != parent && !marked[u.f] && sz[u.f] * 2 >= n)
return find_centro(u.f, node, n);
}
return node;
}
vector<pair<int,int>> v;
void dfs(int node, int parent, int mx, int len) {
v.push_back({mx, len});
for (auto u : graph[node]) {
if (u.f != parent && !marked[u.f])
dfs(u.f, node, max(mx, u.s), len+1);
}
}
ll calc(int node, int parent, int mx, int len) {
v.clear();
dfs(node, parent, mx, len);
sort(v.begin(), v.end());
ll ret = 0;
for (auto u : v) {
int val = u.f - u.s;
ret += get(val - k);
update(u.s, 1);
}
for (auto u : v)
update(u.s, -1);
return ret;
}
void decompose(int node, int parent) {
int n = get_sz(node, parent);
int centro = find_centro(node, parent, n);
ans += calc(centro, centro, 0, 0);
marked[centro] = 1;
for (auto u : graph[centro]) {
if (!marked[u.f])
ans -= calc(u.f, u.f, u.s, 1);
}
for (auto u : graph[centro]) {
if (!marked[u.f])
decompose(u.f, node);
}
}
int main() {
fast
int n, x, y, w;
cin >> n >> k;
graph = vector<vector<pair<int,int>>>(n+1, vector<pair<int,int>>());
for (int i = 1; i < n; i++) {
cin >> x >> y >> w;
graph[x].push_back({y, w});
graph[y].push_back({x, w});
}
decompose(1, 1);
cout << ans*2 << "\n";
}
