#include<bits/stdc++.h>
using namespace std;
int cpu[101][101],j,minn[101],n,k,i,sum,a,b,c,ans;
bool s[101];
int main(){
	cin>>n>>k;
	for(i=1;i<=n;i++){cin>>a>>b>>c;cpu[a][b]=cpu[b][a]=c;sum+=c;}
	memset(minn,0x7f,sizeof(minn)),memset(s,true,sizeof(s));
	minn[1]=0;
	for(i=1;i<=n;i++){
		int t=0;
		for(j=1;j<=n;j++)if(s[j]&&minn[j]<minn[t])t=j;s[t]=false;
		for(j=1;j<=n;j++)if(s[j])minn[j]=min(minn[j],cpu[t][j]);
	}
	for(i=1;i<=n;i++)ans+=minn[i];
	cout<<sum-ans<<endl;
	return 0;
}