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

int y = 0;

struct Graph {
    struct Vertex { int n, x, c; };
    struct Edge { int i, n, c; };
    Graph(int n, int m) : v(n, { -1, 0, 0 }), e(m), n(n), m(0) {}
    void add_edge(int a, int b, int c) {
        e[m] = { b, v[a].n, c };
        v[a].n = m;
        m++;
    }
    int dfs(int i, int p) {
        int x = 0;
        for (int j = v[i].n; j >= 0; j = e[j].n) {
            Edge &o = e[j];
            if (o.i == p) continue;
            v[o.i].c = o.c;
            x += dfs(o.i, i);
        }
        if (x == 0) x = 1;
        y += x * v[i].c;
        return v[i].x = x;
    }
    void solve(int k) {
        //最初のi個を使って長さがl以下のときの最大価値 価値はc*x
        vector<int> dp(k + 1, 0);
        for (int i = 1; i < n; i++) {
            int t = v[i].c, s = v[i].c * v[i].x;
            for (int l = k - t; l >= 0; l--) {
                dp[l + t] = max(dp[l + t], dp[l] + s);
            }
        }
        cout << y + dp[k] << endl;
    }
    vector<Vertex> v;
    vector<Edge> e;
    int n, m;
};

int main() {
    int n, k;
    cin >> n >> k;

    Graph g(n, (n - 1) * 2);
    for (int i = 0; i < n - 1; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        a--; b--;

        g.add_edge(a, b, c);
        g.add_edge(b, a, c);
    }
    g.dfs(0, -1);
    g.solve(k);

    return 0;
}