#include <iostream>
#include <iomanip>
#include <cstdio>
#include <queue>
#include <cstring>
#include <vector>
#include <map>
#include <algorithm>
#include <cctype>
#include <cmath>
#include <bitset>
#include <set>
#include <deque>
#include <stack>
#include <atcoder/all>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < (t); ++i)
#define dsrep(i,t,s) for(int i = (t)-1; i >= (s); --i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
int dx4[4]={1,0,-1,0};
int dy4[4]={0,-1,0,1};
using ll = long long;
using uint = unsigned;
using ull = unsigned long long;
using P = pair<int,int>;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
// const ll mod = 998244353;
const ll mod = 1e9 + 7;

////////////////////////////////////////////
int n, k;
int cnt[101];
struct Edge { ll to, dis; };
vector<Edge> ed[101];
ll dp[101][100005];
ll ans;

int leaf_count(int now, int from, ll t) {
  if(now != 0 && ed[now].size() == 1) {
    ans += t;
    return cnt[now] = 1;
  }

  int sum = 0;
  for(auto x: ed[now]) {
    if(x.to == from) continue;
    sum += leaf_count(x.to, now, t + x.dis);
  }

  return cnt[now] = sum;
}

void calc(int now, int from, int &ind) {
  if(now != 0 && ed[now].size() == 1) return;

  for(auto x: ed[now]) {
    if(x.to == from) continue;
    rep(i, k + 1) {
      if(x.dis <= i) dp[ind + 1][i] = max(dp[ind][i], dp[ind][i - x.dis] + x.dis * cnt[x.to]);
      else dp[ind + 1][i] = dp[ind][i];
    }

    ind++;
    calc(x.to, now, ind);
  }
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n >> k;
  rep(i, n - 1) {
    int a, b, c;
    cin >> a >> b >> c;
    a--; b--;
    ed[a].push_back({b, c});
    ed[b].push_back({a, c});
  }

  leaf_count(0, -1, 0);

  int ind = 0;
  calc(0, -1, ind);

  cout << ans + dp[n - 1][k] << endl;
}