/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2021.04.23 22:40:53
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

vector<vector<array<int,3>>> g;
vector<array<ll,2>> edge;
ll ans;
int dfs(int v,int p = -1) {
    int sum = 0;
    for(auto [u,c,idx] : g[v]) {
        if (u == p) continue;
        int d = dfs(u,v);
        sum += d;
        edge[idx][1] = c*d;
        ans += c*d;
    }
    if (sum == 0) sum++;
    
    return sum;
}
int main() {
    int n,k;cin >> n >> k;
    g.resize(n);
    edge.resize(n-1);
    for (int i = 0; i < n-1; i++) {
        int a,b,c;cin >> a >> b >> c;
        a--;b--;
        g[a].push_back({b,c,i});
        g[b].push_back({a,c,i});
        edge[i][0] = c;
        edge[i][1] = 0;
    }
    dfs(0);
    vector<vector<ll>> dp(n,vector<ll>(k+1));
    for (int i = 0; i < n-1; i++) {
        for (int j = 0; j <= k; j++) {
            dp[i+1][j] = dp[i][j];
            if (edge[i][0] <= j) dp[i+1][j] = max(dp[i+1][j],dp[i][j-edge[i][0]]+edge[i][1]);
        }
    }
    
    
    
    
    cout << ans + dp[n-1][k] << endl;
    return 0;
}