#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5 + 7;
struct Edge{
int v, c;
Edge(int _v, int _c){
v = _v;
c = _c;
}
};
struct Bit{
int d[N];
void update(int x, int val){
for(; x < N; x += x & -x)
d[x] += val;
}
int get(int x){
int res = 0;
for(; x > 0; x -= x & -x)
res += d[x];
return res;
}
};
int n, k, sz[N];
vector<Edge> adj[N];
ll answer = 0;
Bit bit;
bool done[N];
void DfsForCentroid(int u, int p){
sz[u] = 1;
for(Edge e : adj[u]){
int v = e.v;
if (v == p || done[v])
continue;
DfsForCentroid(v, u);
sz[u] += sz[v];
}
}
int FindCentroid(int u, int p, int treeSize){
for(Edge e : adj[u]){
int v = e.v;
if (v == p || done[v])
continue;
if (sz[v] * 2 > treeSize)
return FindCentroid(v, u, treeSize);
}
return u;
}
void Dfs(int u, int p, int len, int maxW, vector<pair<int, int>> &a){
if (done[u])
return;
a.push_back({maxW, len});
for(Edge e : adj[u]){
int v = e.v;
int c = e.c;
if (v == p)
continue;
Dfs(v, u, len + 1, max(maxW, c), a);
}
}
ll Calc(vector<pair<int, int>> &a){
ll res = 0;
sort(a.begin(), a.end());
for(auto p : a){
res += bit.get(p.first - p.second);
bit.update(p.second + k, 1);
}
for(auto p : a)
bit.update(p.second + k, -1);
return res;
}
void Solve(int u){
if (done[u])
return;
DfsForCentroid(u, -1);
u = FindCentroid(u, -1, sz[u]);
vector<pair<int, int>> a;
Dfs(u, -1, 0, 0, a);
answer += Calc(a);
for(Edge e : adj[u]){
a.clear();
int v = e.v;
int c = e.c;
Dfs(v, u, 1, c, a);
answer -= Calc(a);
}
done[u] = 1;
for(Edge e : adj[u])
Solve(e.v);
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> k;
for(int i = 1; i < n; i++){
int u, v, c;
cin >> u >> v >> c;
adj[u].push_back(Edge(v, c));
adj[v].push_back(Edge(u, c));
}
Solve(1);
cout << answer * 2;
return 0;
}
