#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++(i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++(i))
#define REP_R(i, n) for (int i = (int)(n)-1; (i) >= 0; --(i))
#define REP3R(i, m, n) for (int i = (int)(n)-1; (i) >= (int)(m); --(i))
#define ALL(x) ::std::begin(x), ::std::end(x)
using namespace std;

int64_t solve(int n, int k, const vector<vector<pair<int, int64_t> > >& g) {
    vector<pair<int, int64_t> > f;
    int64_t sum_depth = 0;
    auto go = [&](auto&& go, int x, int parent, int64_t depth) -> int {
        int cnt_x = 0;
        for (auto [y, c] : g[x]) {
            if (y != parent) {
                int cnt_y = go(go, y, x, depth + c);
                f.emplace_back(cnt_y, c);
                cnt_x += cnt_y;
            }
        }
        if (cnt_x == 0) {
            sum_depth += depth;
            return 1;
        }
        return cnt_x;
    };
    go(go, 0, -1, 0);
    vector<int64_t> dp(k + 1);
    for (auto [cnt, c] : f) {
        REP_R (i, k + 1 - c) {
            dp[i + c] = max(dp[i + c], dp[i] + cnt * c);
        }
    }
    return sum_depth + dp[k];
}

// generated by oj-template v4.7.2 (https://github.com/online-judge-tools/template-generator)
int main() {
    int n, k;
    cin >> n >> k;
    vector<vector<pair<int, int64_t> > > g(n);
    REP (i, n - 1) {
        int a, b; int64_t c;
        cin >> a >> b >> c;
        -- a;
        -- b;
        g[a].emplace_back(b, c);
        g[b].emplace_back(a, c);
    }
    auto ans = solve(n, k, g);
    cout << ans << endl;
    return 0;
}