#include <bits/stdc++.h>

using namespace std;

using int128 = __int128_t;

#define rep(i, n)         for (int i = 0; i < n; ++i)
#define reps(i, n, s)     for (int i = 0; i < n; i += s)
#define repl(i, l, r)     for (int i = l; i < r; ++i)
#define repsl(i, l, r, s) for (int i = l; i < r; i += s)

#define all(iterable) (iterable).begin(), (iterable).end()

constexpr int dx4[4] = {1, 0, -1, 0};
constexpr int dy4[4] = {0, 1, 0, -1};

constexpr int dx8[8] = {1, 1, 0, -1, -1, -1, 0, 1};
constexpr int dy8[8] = {0, 1, 1, 1, 0, -1, -1, -1};

template <typename T>
void print(const vector<T>& vec, const string sep = " ", const string end = "\n") {
    int n = vec.size();
    rep(i, n) {
        cout << vec[i];
        if (i < n - 1) cout << sep;
        else cout << end;
    }
}

template <typename T>
void read(vector<T>& a, int begin_index, int length) {
    if (a.size() < begin_index + length) a.resize(begin_index + length);
    while (length --> 0) cin >> a[begin_index++];
}
template <typename T>
void read(vector<T>& a) { read(a, 0, a.size()); }

using tree = vector<vector<pair<int, int>>>;

int main() {
    int n, k;
    cin >> n >> k;
    tree t(n);
    rep(i, n - 1) {
        int u, v, c;
        cin >> u >> v >> c;
        --u, --v;
        t[u].push_back({v, c});
        t[v].push_back({u, c});
    }
    long long ans = 0;
    vector<long long> val(n, 0), prd(n, 0);
    auto dfs = [&](auto self, int u, int p, int c) -> int {
        val[u] = c;
        int leaves = 0;
        for (auto &[v, c] : t[u]) {
            if (v == p) continue;
            leaves += self(self, v, u, c);
        }
        if (leaves == 0) ++leaves;
        ans += prd[u] = val[u] * leaves;
        return leaves;
    };
    dfs(dfs, 0, -1, 0);
    vector<long long> dp(k + 1, 0);
    repl(i, 1, n) for (int j = k; j >= val[i]; --j) {
        dp[j] = max(dp[j], dp[j - val[i]] + prd[i]);
    }
    ans += *max_element(all(dp));
    cout << ans << '\n';
    return 0;
}