#include <bits/stdc++.h>

#define For(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rFor(i, a, b) for (int i = (int)(a)-1; i >= (int)(b); --i)
#define rep(i, n) For((i), 0, (n))
#define rrep(i, n) rFor((i), (n), 0)
#define fi first
#define se second

using namespace std;

typedef long long lint;
typedef unsigned long long ulint;
typedef pair<int, int> pii;
typedef pair<lint, lint> pll;

template <class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
bool chmin(T &a, const T &b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template <class T>
T div_floor(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a >= 0 ? a / b : (a + 1) / b - 1;
}
template <class T>
T div_ceil(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a > 0 ? (a - 1) / b + 1 : a / b;
}

template <typename T>
struct coord_comp {
    vector<T> v;
    bool sorted = false;

    coord_comp() {}

    int size() { return v.size(); }

    void add(T x) { v.push_back(x); }

    void build() {
        sort(v.begin(), v.end());
        v.erase(unique(v.begin(), v.end()), v.end());
        sorted = true;
    }

    int get_idx(T x) {
        assert(sorted);
        return lower_bound(v.begin(), v.end(), x) - v.begin();
    }

    T &operator[](int i) { return v[i]; }
};

constexpr lint mod = 1000000007;
constexpr lint INF = mod * mod;
constexpr int MAX = 200010;

vector<int> G[110];
map<pii, int> idx;
lint c[110], d[110], leaf[110], sum;

void dfs(int v, int pv, lint dep) {
    leaf[v] = 0;
    bool flag = false;
    for (auto nv : G[v])
        if (nv != pv) {
            flag = true;
            int e = idx[{v, nv}];
            dfs(nv, v, dep + c[e]);
            leaf[v] += leaf[nv];
            d[e] = c[e] * leaf[nv];
        }
    if (!flag) {
        leaf[v] = 1;
        sum += dep;
    }
}

int main() {
    int n, K;
    scanf("%d%d", &n, &K);
    rep(i, n - 1) {
        int a, b;
        scanf("%d%d%lld", &a, &b, &c[i]);
        --a;
        --b;
        G[a].push_back(b);
        G[b].push_back(a);
        idx[{a, b}] = i;
        idx[{b, a}] = i;
    }
    dfs(0, -1, 0);

    vector<lint> dp(K + 1, -1);
    dp[0] = 0;
    rep(i, n - 1) {
        vector<lint> nxt(K + 1, -1);
        rep(j, K + 1) if (dp[j] >= 0) {
            chmax(nxt[j], dp[j]);
            if (j + c[i] <= K) chmax(nxt[j + c[i]], dp[j] + d[i]);
        }
        swap(dp, nxt);
    }
    rep(i, K) chmax(dp[i + 1], dp[i]);
    printf("%lld\n", sum + dp[K]);
}