#include <bits/stdc++.h>
using namespace std;
#define int long long
int fw[100005], k;
vector<int> loc;
void update(int x, int v) {
for(x++; x < 100005; x += x&-x) {fw[x] += v; loc.push_back(x);}
}
int query(int x) {
int ans = 0;
for(x++; x; x -= x&-x) ans += fw[x];
return ans;
}
int query(int x, int y) {
return query(y) - query(x-1);
}
void reset() {
for(int i : loc) fw[i] = 0;
loc.clear();
}
vector<pair<int, int>> adj[100000];
int sz[100000], used[100000], ans;
vector<pair<int, int>> v[100000];
int size(int x, int pa) {
sz[x] = 1;
for(auto i : adj[x]) if(i.first != pa && !used[i.first]) sz[x] += size(i.first, x);
return sz[x];
}
int centroid(int x, int pa, int n) {
for(auto i : adj[x]) if(i.first != pa && !used[i.first]) {
if(sz[i.first] > n/2) return centroid(i.first, x, n);
}
return x;
}
void dfs(int x, int p, int d, int mx, int pp) {
v[pp].push_back({mx, d});
for(auto i : adj[x]) if(i.first != p && !used[i.first]) dfs(i.first, x, d+1, max(mx, i.second), pp);
}
void decomp(int x) {
int c = centroid(x, -1, size(x, -1));
for(auto i : adj[c]) if(!used[i.first]) dfs(i.first, c, 1, i.second, i.first);
vector<pair<int, int>> v2;
v2.push_back({0, 0});
for(auto i : adj[c]) if(!used[i.first]) {
sort(v[i.first].begin(), v[i.first].end());
for(auto j : v[i.first]) {
if(j.first-j.second-k >= 0) ans -= query(j.first-j.second-k);
update(j.second, 1);
v2.push_back(j);
}
v[i.first].clear();
reset();
}
sort(v2.begin(), v2.end());
for(auto j : v2) {
if(j.first-j.second-k >= 0) ans += query(j.first-j.second-k);
update(j.second, 1);
}
reset();
used[c] = 1;
for(auto i : adj[c]) if(!used[i.first]) decomp(i.first);
}
int32_t main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, x, y, w;
cin >> n >> k;
for(int i = 1; i < n; i++) {
cin >> x >> y >> w;
x--; y--;
adj[x].push_back({y, w});
adj[y].push_back({x, w});
}
decomp(0);
cout << ans*2 << '\n';
}
