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

using pl = pair<ll,ll>;
using tl = tuple<ll,ll,ll>;

void chmax(ll &a, ll b) {
    a = max(a, b);
}

void solve() {
    ll n, k;
    cin >> n >> k;
    vector<vector<tl>> G(n);
    vector<ll> weight(n-1);
    rep(i, 0, n-1) {
        ll u, v, w;
        cin >> u >> v >> w;
        u--; v--;
        G[u].push_back({v, w, i});
        G[v].push_back({u, w, i});
        weight[i] = w;
    }
    vector<ll> cnt(n-1, 0), sub(n, 0);
    auto dfs1 = [&](auto dfs1, ll cur, ll par) -> ll {
        ll res = 0;
        bool leaf = true;
        for(auto [to, cost, id] : G[cur]) {
            if(to == par) continue;
            leaf = false;
            res += dfs1(dfs1, to, cur);
            cnt[id] += sub[to];
        }
        if(leaf) res = 1;
        sub[cur] = res;
        return res;
    };
    dfs1(dfs1, 0, -1);
    vector<ll> depth(n, 0);
    ll sum = 0;
    auto dfs2 = [&](auto dfs2, ll cur, ll par) -> void {
        bool leaf = true;
        for(auto [to, cost, id] : G[cur]) {
            if(to == par) continue;
            leaf = false;
            depth[to] = depth[cur] + cost;
            dfs2(dfs2, to, cur);
        }
        if(leaf) sum += depth[cur];
    };
    dfs2(dfs2, 0, -1);
    vector dp(n+10, vector<ll>(k+100, 0));
    rep(i, 0, n-1) {
        rep(j, 0, k+1) chmax(dp[i+1][j], dp[i][j]);
        rep(j, 0, k) if(j+weight[i] <= k) chmax(dp[i+1][j+weight[i]], dp[i][j]+cnt[i]*weight[i]);
    }
    ll ans = 0;
    rep(i, 0, k+1) chmax(ans, dp[n-1][i]);
    cout << sum+ans << endl;
}

int main() {
    solve();
    return 0;
}