#include <iostream>
#include <bits/stdc++.h>


using namespace std;

ifstream fapm("apm.in");
ofstream gapm("apm.out");


class Graf
{
    int nrNoduri;
    int nrMuchii;

    vector<vector<pair<int,int>>> costs;



public:

    void citire_apm();
    Graf(int n, int m);
    void APM();
    int nodCostMin(vector<int> &helper, vector<bool> &inMst);



};

Graf::Graf(int n, int m)
{
    this->nrNoduri = n;
    this->nrMuchii = m;
    this->costs.resize(nrNoduri + 1);

    int nod1, nod2, cost;
    pair<int,int> temp;

    for(int i = 0; i < this->nrMuchii; i++)
    {
        fapm>>nod1>>nod2>>cost;

        temp.first = nod2;
        temp.second = cost;

        this->costs[nod1].push_back(temp);
        temp.first = nod1;
        this->costs[nod2].push_back(temp);
    }
}

/*void Graf::citire_apm()
{
    costs.resize(nrNoduri + 1);
    int nod1, nod2, cost;
    pair<int,int> temp;

    fapm>>nrNoduri>>nrMuchii;

    for(int i = 0; i < nrMuchii; i++)
    {
        fapm>>nod1>>nod2>>cost;

        temp.first = nod2;
        temp.second = cost;

        costs[nod1].push_back(temp);
        temp.first = nod1;
        costs[nod2].push_back(temp);
    }

}*/



int Graf::nodCostMin(vector<int> &helper, vector<bool> &inMst)
{
    int minimum, indexOfMin;
    minimum  = INT_MAX;

    for(int i = 1; i <= nrNoduri; i++)
        if(inMst[i] == false && helper[i] < minimum)
        {
            minimum = helper[i];
            indexOfMin = i;
        }

    return indexOfMin;
}
void Graf::APM()
{
    vector<int> parent;         //un fel de vector de tati, aici va fi apm-ul
    vector<bool> inMst;         //un fel de visited
    vector<int> helper;         //cele mai mici costuri din nodul curent
                                //se updateaza la fiecare pas

    for(int i = 0 ; i <= nrNoduri; i++)
    {
        helper.push_back(INT_MAX);
        inMst.push_back(false);
        parent.push_back(0);
    }


    helper[1] = 0;
    parent[1] = -1;
    for(int i = 1 ; i <= nrNoduri; i++)
    {
        int nextVertex = nodCostMin(helper, inMst);  //gasim urmatorul nod cu muchia de cost minim
        inMst[nextVertex] = true;

        int sz = costs[nextVertex].size();
        for(int j = 0; j < sz; j++)
        {   int temp1 = costs[nextVertex][j].first;
            int temp2 = costs[nextVertex][j].second;

            if(inMst[temp1] == false && temp2 < helper[temp1])
            {
                parent[temp1] = nextVertex;
                helper[temp1] = temp2;
            }

        }

    }
    int sum = 0;
    for(int  i = 2; i <= nrNoduri; i++)
        sum += helper[i];



    gapm<<sum<<"\n";
    gapm<<nrNoduri - 1<<"\n";
    for(int  i = 2; i <= nrNoduri; i++)
        gapm<<parent[i]<<" "<<i<<"\n";

}


int main()
{
    int n, m;
    fapm>>n>>m;

    Graf G(n, m);

    G.APM();

    return 0;
}