#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cassert>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

int n, k;
int par[101];
int par_cost[101];
bool used[101];
int ch[101];

struct edge{
    int to, cost;
};

vector<edge> g[101];

void dfs(int v){
    used[v] = true;
    int cnt = 0;
    for(edge e : g[v]){
        if(!used[e.to]){
            par_cost[e.to] = e.cost;
            par[e.to] = v;
            dfs(e.to);
            ch[v] += ch[e.to];
            cnt++;
        }
    }
    if(cnt == 0) ch[v] = 1;
}

using P = pair<ll, int>;
ll dp[101][100005];

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    cin >> n >> k;
    for(int i = 0; i < n-1; i++){
        int a, b, c; cin >> a >> b >> c; a--; b--;
        g[a].push_back(edge{b, c});
        g[b].push_back(edge{a, c});
    }
    dfs(0);
    vector<ll> w(n-1), v(n-1);
    for(int i = 1; i < n; i++){
        w[i-1] = par_cost[i];
        v[i-1] = par_cost[i]*ch[i];
    }
    for(int i = 0; i < n-1; i++){
        for(int j = 0; j <= k; j++){
            chmax(dp[i+1][j], dp[i][j]);
            if(j+w[i] <= k) chmax(dp[i+1][j+w[i]], dp[i][j]+v[i]);
        }
    }
    ll ans = 0;
    for(int i = 0; i <= k; i++) chmax(ans, dp[n-1][i]);
    for(int i = 1; i < n; i++){
        ans += v[i-1];
    }
    cout << ans << endl;
}