#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i,n)for (int i = 0; i < int(n); ++i)
#define rrep(i,n)for (int i = int(n)-1; i >= 0; --i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
template<class T> void chmax(T& a, const T& b) {a = max(a, b);}
template<class T> void chmin(T& a, const T& b) {a = min(a, b);}
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, k;
    cin >> n >> k;
    vector<vector<P>> to(n);
    rep(i, n - 1) {
        int a, b, c;
        cin >> a >> b >> c;
        a--, b--;
        to[a].emplace_back(b, c);
        to[b].emplace_back(a, c);
    }
    ll score = 0;
    vector<pair<int, ll>> items;
    auto dfs = [&](auto&& self, int u=0, int p=-1) -> int {
        if (p != -1 && to[u].size() == 1) return 1;
        int ret = 0;
        for(auto [v, c]: to[u]) if (v != p) {
            int r = self(self, v, u);
            items.emplace_back(c, ll(c) * r);
            ret += r;
            score += ll(c) * r;
        }
        return ret;
    };
    dfs(dfs);
    VL dp(k + 1);
    for(auto [w, v]: items) {
        rrep(i, k - w + 1) {
            chmax(dp[i + w], dp[i] + v);
        }
    }
    cout << score + dp[k] << '\n';
}