#include <iostream>

#include <cstdio>

#include <cmath>

#include <algorithm>

#include <stack>

#include <queue>

#include <map>

#include <cstring>

#include <iomanip>

const int N = 1e3 + 10;

using namespace std;

const int INF = 0x3f3f3f3f;

using namespace std;

struct node 
{
	int data;
	
	int to;
};
int n , q , u , v , w ;

int dp[N][N] , son[N];

vector<node> vc[N];

void dfs (int u , int fa)
{
	son[u] = 1;
	
	dp[u][1] = 0;
	
	for(int i = 0 ; i < vc[u].size() ; i++)
	{
		int v = vc[u][i].to;
		
		if(v ==fa)continue;
		
		dfs(v , u);
		
		son[u] += son[v];
		
		for(int j = son[u] ; j >= 1 ; j--)
		{
			for(int k = 1 ; k <= min( j - 1 , son[v]) ; k++)
			{
				dp[u][j] = max(dp[u][j] , dp[u][j-k] + dp[v][k] + vc[u][i].data);
			}
		}
	}
}

int main()
{
	cin >> n >> q ;
	
	memset(dp , -INF , sizeof(dp));
	
	for(int i = 1 ; i < n ; i++)
	{
		cin >> u >> v >> w ;
		
		vc[u].push_back((node){w , v});
		
		vc[v].push_back((node){w , u});
	}
	
	dfs( 1 , 0 );
	
	cout << dp[1][q + 1];
	    
	return 0;
}