#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

template <class F> struct REC {
  F f;
  REC(F &&f_) : f(std::forward<F>(f_)) {}
  template <class... Args> auto operator()(Args &&... args) const {
    return f(*this, std::forward<Args>(args)...);
  }
};

int main() {
    int n, k;
    cin >> n >> k;
    vector<vector<pair<int, int>>> G(n);
    for (int i = 0; i < n-1; ++i) {
        int a, b, c;
        scanf("%d %d %d", &a, &b, &c);
        a--; b--;
        G[a].emplace_back(b, c);
        G[b].emplace_back(a, c);
    }
    vector<ll> cnt(n, 0), val(n);
    int sum = 0;
    REC([&](auto &&f, int x, int p, int d) -> void {
        int leaf = 1;
        for (auto &&[y, c] : G[x]) {
            if(y == p) continue;
            val[y] = c;
            f(y, x, d+c);
            cnt[x] += cnt[y];
            leaf = 0;
        }
        if(leaf) cnt[x]++, sum += d;
    })(0, -1, 0);
    vector<ll> dp(k+1, -INF<ll>);
    dp[0] = 0;
    for (int i = 1; i < n; ++i) {
        ll c = val[i], v = cnt[i]*val[i];
        for (ll j = k-c; j >= 0; --j) {
            dp[j+c] = max(dp[j+c], dp[j]+v);
        }
    }
    cout << sum+*max_element(dp.begin(),dp.end()) << "\n";
    return 0;
}