#include <bits/stdc++.h>
using namespace std;
int ans;
vector<pair<int,int>> adj[1005];
int k;
void dfs(int n, int p, int longest, int cur_dist) {
if (p != -1 and longest-cur_dist >= k) ans++;
for (auto i:adj[n]) {
if (i.first != p) {
int tmp = max(longest, i.second);
dfs(i.first, n, tmp, cur_dist+1);
}
}
}
int main() {
int n; cin >> n;
cin >> k;
for (int i = 0; i < n-1; i++) {
int x, y, z; cin >> x >> y >> z;
x--;y--;
adj[x].push_back({y,z});
adj[y].push_back({x,z});
}
ans = 0;
for (int i = 0; i < n; i++) dfs(i, -1, 0, 0);
cout << ans;
}
