#include <bits/stdc++.h>
using namespace std;

using P = pair<int, int>;

int n, k;
vector<vector<P>> g;
vector<long long> c, cnt, memo;

long long solve();
int dfs(int now = 0, int par = -1);

int main() {
  cin >> n >> k;
  g.resize(n);
  for (int i = 1; i < n; ++i) {
    int a, b, p;
    cin >> a >> b >> p;
    g[--a].emplace_back(--b, i - 1);
    g[b].emplace_back(a, i - 1);
    c.push_back(p);
  }
  cout << solve() << endl;
  return 0;
}

long long solve() {
  cnt.assign(n, 0);
  memo.assign(n - 1, 0);
  dfs();
  long long res = 0;
  vector<long long> dp(k + 1, -1e17);
  dp[0] = 0;
  for (int i = 0; i < n - 1; ++i) {
    res += memo[i] * c[i];
    vector<long long> v = dp;
    for (int j = c[i]; j <= k; ++j)
      v[j] = max(v[j], dp[j - c[i]] + memo[i] * c[i]);
    swap(v, dp);
  }
  long long tmp = -1;
  for (auto p : dp) tmp = max(tmp, p);
  return res + tmp;
}

int dfs(int now, int par) {
  int leaf = 0;
  for (auto [to, id] : g[now])
    if (to != par) {
      int tmp = dfs(to, now);
      leaf += tmp;
      memo[id] = tmp;
    }
  if (!leaf) ++leaf;
  return cnt[now] = leaf;
}