#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    // (w,v) = (c(e), leaf_cnt(e.c) * c(e))
    int N,K; cin >> N >> K;
    vector<vector<pair<int,int>>> G(N);
    rep(i,N-1) {
        int a,b,c; cin >> a >> b >> c; a--; b--;
        G[a].push_back({b, c});
        G[b].push_back({a, c});
    }

    int ROOT = 0, SUM = 0;
    vector<int> leaf_cnt(N, 0);
    vector<pair<int,int>> wv;
    function<void(int,int)> get_leaf = [&](int v, int p) -> void {
        int is_leaf = 1;
        for(auto [to, c] : G[v]) {
            if(to != p) {
                is_leaf = 0;
                get_leaf(to, v);
                leaf_cnt[v] += leaf_cnt[to];
            }
        }
        leaf_cnt[v] += is_leaf;
        for(auto [to, c] : G[v]) {
            if(to != p) {
                wv.push_back({c, leaf_cnt[to] * c});
                SUM += leaf_cnt[to] * c;
            }
        }
    }; get_leaf(ROOT, -1);

    vector<int> dp(K + 1, 0);
    for(auto [w, v] : wv) {
        vector<int> nt = dp;
        for(int x = 0; x <= K; x++)
            if(x + w <= K) nt[x + w] = max(nt[x + w], dp[x] + v);
        swap(dp, nt);
    }

    cout << SUM + *max_element(dp.begin(), dp.end()) << endl;
}