#include <fstream>
#include <vector>
#define NMAX 200002
#define INF (1<<30)
using namespace std;
ifstream  fin("apm.in");
ofstream fout("apm.out");
int N,M,H,ans,cnt,heap[NMAX],pozitie[NMAX],viz[NMAX],tata[NMAX];
vector<int> cost(NMAX,INF);
vector<pair<int,int>> graph[NMAX];

struct solutie
{
    int x,y;
} sol[NMAX];

void citire()
{
    fin>>N>>M;

    int X,Y,C;
    for(int i=1; i<=M; i++)
    {
        fin>>X>>Y>>C;
        graph[X].push_back({Y,C});
        graph[Y].push_back({X,C});
    }
}

void urcare(int poz)
{
    while(poz/2>=1 && cost[heap[poz]]<cost[heap[poz/2]])
    {
        swap(pozitie[heap[poz]],pozitie[heap[poz/2]]);
        swap(heap[poz],heap[poz/2]);
        poz=poz/2;
    }
}

void coborare(int poz)
{
    while(2*poz<=H)
    {
        int r=2*poz;
        if(r+1<=H && cost[heap[r+1]]<cost[heap[r]])
        {
            r++;
        }

        if(cost[heap[r]]<cost[heap[poz]])
        {
            swap(pozitie[heap[poz]],pozitie[heap[r]]);
            swap(heap[poz],heap[r]);
            poz=r;
        }
        else
        {
            break;
        }
    }
}

void adaugare_heap(int nod)
{
    H++;
    heap[H]=nod;
    pozitie[nod]=H;
    urcare(H);
}

void eliminare_minim()
{
    pozitie[heap[1]]=0;
    pozitie[heap[H]]=1;
    heap[1]=heap[H];
    H--;
    coborare(1);
}

int main()
{
    citire();

    cost[1]=0;
    adaugare_heap(1);
    ans=cnt=0;

    while(H)
    {
        int nod=heap[1];
        eliminare_minim();

        if(viz[nod])
        {
            continue;
        }

        ans+=cost[nod];
        viz[nod]=1;

        if(tata[nod])
        {
            cnt++;
            sol[cnt].x=tata[nod];
            sol[cnt].y=nod;
        }

        for(int i=0; i<graph[nod].size(); i++)
        {
            int next_nod=graph[nod][i].first;

            if(!viz[next_nod] && cost[next_nod]>graph[nod][i].second)
            {
                cost[next_nod]=graph[nod][i].second;
                tata[next_nod]=nod;

                if(!pozitie[next_nod])
                {
                    adaugare_heap(next_nod);
                }
                else
                {
                    urcare(pozitie[next_nod]);
                }
            }
        }
    }

    fout<< ans << "\n";

    fout<< cnt << "\n";

    for(int i=1; i<=cnt; i++)
    {
        fout<< sol[i].x << " " << sol[i].y << "\n";
    }

    return 0;
}