#include <fstream>
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
int n, m;
long long rez;
struct muchii
{
    int x, y, c;
};
muchii muc[400005];
int t[200005], rang[200005];
vector < pair < int , int > > arbore;
bool sortare(muchii m1, muchii m2)
{
    return m1.c < m2.c;
}
int Root(int x)
{
    if(t[x] == 0)
        return x;
    else
    {
        int a = Root(t[x]);
        t[x] = a;
        return a;
    }
}
int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> muc[i].x >> muc[i].y >> muc[i].c;
    }
    sort(muc + 1, muc + m + 1, sortare);
    /*for(int i = 1; i <= m; i++)
    {
        cout << muc[i].c << " ";
    }*/
    int cnt = 0;
    for(int i = 1; i <= m && cnt < n; i++)
    {
        int r1 = Root(muc[i].x), r2 = Root(muc[i].y);
        if(r1 != r2)
        {
            cnt++;
            rez += muc[i].c;
            arbore.push_back(make_pair(muc[i].x, muc[i].y));
            if(rang[r1] > rang[r2])
            {
                t[r2] = r1;
            }
            else
            {
                t[r1] = r2;
                if(rang[r1] == rang[r2])
                {
                    rang[r2]++;
                }
            }
        }
    }
    fout << rez << endl;
    fout << arbore.size() << endl;
    for(int i = 0; i < arbore.size(); i++)
    {
        fout << arbore[i].first << " " << arbore[i].second << endl;
    }
    return 0;
}