#include <iostream>
#include <cstring>
#include <vector>
using namespace std;
const int N = 105,M = 2 * N;
int n,q;
int h[N],e[M],ne[M],w[M],idx;
int f[N][M];
vector<int> sons[N];
vector<int> sons_w[N];
void add(int a,int b,int c){
	e[idx] = b,w[idx] = c,ne[idx] = h[a],h[a] = idx++;
}
int dfs(int i,int j){
	if(sons[i].size() == 0) return 0;
	if(j == 0) return 0;
	if(f[i][j] > 0) return f[i][j];
	for(int k=0;k<=j;k++){
		if(k == 0) f[i][j] = max(f[i][j],dfs(sons[i][1],j - 1) + sons_w[i][1]);
		else if(k == j) f[i][j] = max(f[i][j],dfs(sons[i][0],j - 1) + sons_w[i][0]);
		f[i][j] = max(f[i][j],dfs(sons[i][0],k - 1) + sons_w[i][0] + dfs(sons[i][1],j - k - 1) + sons_w[i][1]);
	}
	return f[i][j];
}
void build(int u,int father){
	for(int i=h[u];i!=-1;i=ne[i]){
		int j = e[i];
		if(j == father) continue;
		sons[u].push_back(j);
		sons_w[u].push_back(w[i]);
		build(j,u);
	}
}
int main(){
	scanf("%d %d",&n,&q);
	memset(h,-1,sizeof(h));
	for(int i=1;i<n;i++){
		int a,b,c;
		scanf("%d %d %d",&a,&b,&c);
		add(a,b,c);
		add(b,a,c);
	}
	build(1,-1);
	printf("%d",dfs(1,q));
	return 0;
}