#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

ifstream f("apm.in");
ofstream g("apm.out");

const int INF = 2100000000;

int n, m;
vector <pair <int, int>> * lv;

class Edge{

public:

    int first;
    int second;

    int price;

    Edge(int f, int s, int p): first(f), second(s), price(p) {};
};

int min_price;
vector <Edge> selected;
int * pair_node;

int * d;
bool * v;

int * q_pos;
int * q;
int q_dim;

int pop(){

    swap(q_pos[q[1]], q_pos[q[q_dim]]);
    swap(q[1], q[q_dim]);

    q_dim -= 1;

    bool ok = 0;

    int pos = 1;
    while(!ok)

        if(pos * 2 > q_dim && pos * 2 + 1 > q_dim)

            ok = true;

        else if(pos * 2 > q_dim){

            if(d[q[pos * 2 + 1]] > d[q[pos]])

                ok = true;

            else{

                swap(q_pos[q[pos * 2 + 1]], q_pos[q[pos]]);
                swap(q[pos * 2 + 1], q[pos]);

                pos *= 2;
                pos += 1;
            }
        }
        else if(pos * 2 + 1 > q_dim){

            if(d[q[pos * 2]] > d[q[pos]])

                ok = true;

            else{

                swap(q_pos[q[pos * 2]], q_pos[q[pos]]);
                swap(q[pos * 2], q[pos]);

                pos *= 2;
            }
        }
        else{

            if(d[q[pos]] < d[q[pos * 2]] && d[q[pos]] < d[q[pos * 2 + 1]])

                ok = true;

            else if(d[q[pos * 2]] < d[q[pos * 2 + 1]]){

                swap(q_pos[q[pos * 2]], q_pos[q[pos]]);
                swap(q[pos * 2], q[pos]);

                pos *= 2;
            }
            else{

                swap(q_pos[q[pos * 2 + 1]], q_pos[q[pos]]);
                swap(q[pos * 2 + 1], q[pos]);

                pos *= 2;
                pos += 1;
            }
        }

    return q[q_dim + 1];
}

void update(int node){

    int pos = q_pos[node];

    bool ok = 0;

    while(!ok)

        if(pos / 2 == 0 || d[q[pos]] > d[q[pos / 2]])

            ok = true;
        else{

            swap(q_pos[q[pos]], q_pos[q[pos / 2]]);
            swap(q[pos], q[pos / 2]);

            pos /= 2;
        }
}

void prim(){

    while(q_dim){

        int current_node = pop();
        v[current_node] = 1;


        if(current_node != 1){

            min_price += d[current_node];
            selected.push_back(Edge(current_node, pair_node[current_node], d[current_node]));
        }

        for(int i = 0; i < lv[current_node].size(); i++){

            int next_node = lv[current_node][i].first;
            int new_price = lv[current_node][i].second;

            if(!v[next_node] && d[next_node] > new_price){

                d[next_node] = new_price;
                pair_node[next_node] = current_node;

                update(next_node);
            }
        }
    }
}

int main(){

    f >> n >> m;

    lv = new vector <pair <int ,int>> [n + 1];

    d = new int [n + 1];
    v = new bool [n + 1];

    pair_node = new int [n + 1];

    q = new int [n + 1];
    q_pos = new int [n + 1];
    q_dim = n;

    for(int i = 1 ; i <= n; i++){

        d[i] = INF;
        v[i] = 0;

        q[i] = i;
        q_pos[i] = i;
    }

    int x, y, c;
    for(int i = 0; i < m ; i++){

        f >> x >> y >> c;

        lv[x].push_back(make_pair(y, c));
        lv[y].push_back(make_pair(x, c));
    }

    prim();

    g << min_price << '\n';

    g << selected.size() << '\n';
    for(int i = 0; i < selected.size(); i++)

        g << selected[i].first << " " << selected[i].second << '\n';


    return 0;
}