#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(ri,n) for(int ri = (int)(n-1); ri >= 0; ri--)
#define rep2(i,x,n) for(int i = (int)(x); i < (int)(n); i++)
#define rrep2(ri,x,n) for(int ri = (int)(n-1); ri >= (int)(x); ri--)
#define repit(itr,x) for(auto itr = x.begin(); itr != x.end(); itr++)
#define rrepit(ritr,x) for(auto ritr = x.rbegin(); ritr != x.rend(); ritr++)
#define ALL(x) x.begin(), x.end()
using ll = long long;
using namespace std;

int dfs(vector<vector<tuple<int, int, int>>> &tree, vector<ll> &p, ll &ans, int now, int bf, int adans) {
  int res = 0;
  bool f = false;
  for(auto [nx, c, i] : tree.at(now)) {
    if(nx == bf) continue;
    int r = dfs(tree, p, ans, nx, now, adans+c);
    p.at(i) = r*c;
    res += r;
    f = true;
  }
  if(!f) {
    ans += adans;
    res++;
  }
  // cerr << now << " " << res << endl;
  return res;
}

int main() {
  int n, k;
  cin >> n >> k;
  vector tree(n, vector<tuple<int, int, int>>());
  vector<int> ip(n-1);
  rep(i, n-1) {
    int a, b, c;
    cin >> a >> b >> c;
    a--; b--;
    tree.at(a).push_back({b, c, i});
    tree.at(b).push_back({a, c, i});
    ip.at(i) = c;
  }
  vector<ll> p(n-1, 0);
  ll ans = 0;
  dfs(tree, p, ans, 0, -1, 0);
  // rep(i, n-1) cerr << p.at(i) << " ";
  // cerr << endl;
  // cerr << ans << endl;
  vector dp(n, vector<ll>(k+1, 0));
  rep(i, n-1) {
    rep(j, k+1) {
      dp.at(i+1).at(j) = max(dp.at(i+1).at(j), dp.at(i).at(j));
      if(j + ip.at(i) <= k) {
        dp.at(i+1).at(j+ip.at(i)) = max(dp.at(i+1).at(j+ip.at(i)), dp.at(i).at(j)+p.at(i));
      }
    }
  }
  ans += dp.back().back();
  cout << ans << endl;
  return 0;
}