#include<bits/stdc++.h>
using namespace std;
const int N=2e3+5;
const int M=3e3+5; 
int n,m,fa[N],cnt,ans;
struct node{
	int x,y,w;
}edge[M];
bool cmp(node a,node b){
	return a.w<b.w;
}
int find(int x){
	if(fa[x]==x){
		return x;
	}
	return fa[x]=find(fa[x]);
}
void unionn(int x,int y){
	int fx=find(x);
	int fy=find(y);
	fa[fx]=fy;
	return;
}
void kruskal(){
	for(int i=1;i<=n;i++){
	    fa[i]=i;
	}
	sort(edge+1,edge+m+1,cmp);
	for(int i=1;i<=m;i++){
		int x=edge[i].x;
		int y=edge[i].y;
		if(find(x)!=find(y)){
		    unionn(x,y);
			ans+=edge[i].w;
			cnt++;
		}
		if(cnt==n-1){
			return;
		}
	}
	return;
}
int main(){
    cin>>n>>m;
    for(int i=1;i<=m;i++){
	    cin>>edge[i].x>>edge[i].y>>edge[i].w;
	}
	kruskal();
	cout<<ans;
	return 0;
}