#include<iostream>
#include<set>
#include<vector>
using namespace std;
main(){
	int n,m,i,j,k,c0,c1,w;
	cin>>n>>m;
	set<pair<int,pair<int,int> > >r;
	vector<bool>c(n+1,false);
	for(;m;--m){
		cin>>i>>j>>k;
		r.insert({k,{i,j}});
	}
	c[r.begin()->second.first]=true;
	c[r.begin()->second.second]=true;
	w=r.begin()->first;
	r.erase(r.begin());
	for(k=0;k<n-2;++k)
		for(auto p:r){
			i=p.second.first;
			j=p.second.second;
		if(c[i]!=c[j]){
			w+=p.first;c[i]=1;c[j]=1;
			r.erase(p);break;}}
	cout<<w;
}