#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

struct muchie
{
    int x,y,c;
};
muchie a[400005];
int t[200005];
int n,m,cost;

bool Cmp(muchie a, muchie b)
{
    return a.c < b.c;
}

void Citire()
{
    int i,x1,y1,c1;
    ifstream fin("apm.in");
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x1>>y1>>c1;
        a[i].x=x1;
        a[i].y=y1;
        a[i].c=c1;
    }
    fin.close();
}

void Unifica(int va1, int va2)
{
    for(int i=1;i<=n;i++)
        if(t[i]==va2)
            t[i]=va1;
}

void Kruskal()
{
    sort(a+1,a+m+1,Cmp);
    int i,v1,v2,k;
    k=n-1;
    for(i=1;i<=n;i++)
        t[i]=i;
    for(i=1; k>0 && i<=m;i++)
    {
        v1=a[i].x;
        v2=a[i].y;
        if(t[v1]!=t[v2])
        {
            Unifica(t[v1],t[v2]);
            cout<<v1<<" "<<v2<<"\n";
            cost+=a[i].c;
            k--;
        }
    }
}

int main()
{
    Citire();
    Kruskal();
    cout<<cost;
    return 0;
}