#include<bits/stdc++.h>
using namespace std;
const int N=105;
int n,m,k,s,t,f[N][N],a[N],sz[N];
vector<pair<int,int>> e[N];
void dfs(int u,int fa){
	sz[u]=1;
	for (auto &i:e[u]){
		int v=i.first;
		int w=i.second;
		if (v==fa) continue;
		dfs(v,u);
		for (int i=sz[u]-1;i>=0;--i)
			for (int j=0;j<sz[v];++j)
				f[u][i+j+1]=max(f[u][i+j+1],f[u][i]+f[v][j]+w);
		sz[u]+=sz[v];
	}
}
int main(){
	cin>>n>>m;
	for (int i=1;i<n;++i){
		cin>>s>>t>>k;
		e[s].push_back({t,k});
		e[t].push_back({s,k});
	}
	dfs(1,0);
	cout<<f[1][m];
}