#include <bits/stdc++.h>
using namespace std;

ifstream fin("apm.in");
ofstream fout("apm.out");

const int N_MAX = 2e5 + 1;

int id[N_MAX], sz[N_MAX];

int dsu_find(int node)
{
    int root = node;

    while(id[root] != 0)
        root = id[root];

    int aux = node;

    while(node != root)
    {
        aux = id[node];
        id[node] = root;
        node = aux;
    }

    return root;
}


bool dsu_union(int x, int y)
{
    int root_x = dsu_find(x);
    int root_y = dsu_find(y);

    if(root_x == root_y) return false;

    if(sz[root_x] < sz[root_y]) swap(root_x, root_y);

    sz[root_x] += sz[root_y];
    id[root_y] = root_x;

    return true;
}


int N, M;

struct Muchie{
    int x, y, c;
};

vector<Muchie> graph;

vector<pair<int, int>> answer;

int main()
{
    fin >> N >> M;

    for(int i = 1; i <= M; ++i)
    {
        Muchie m;
        fin >> m.x >> m.y >> m.c;

        graph.push_back(m);
    }

    sort(graph.begin(), graph.end(), [](Muchie& A, Muchie& B){return A.c < B.c;});

    long long min_cost = 0;

    for(size_t i = 0; i < graph.size() && answer.size() != (size_t)N - 1; ++i)
    {
        if(dsu_union(graph[i].x, graph[i].y) == true)
        {
            min_cost += graph[i].c;
            answer.push_back({graph[i].x, graph[i].y});
        }
    }

    fout << N - 1 << '\n';
    fout << min_cost << '\n';

    for(auto& muchie : answer)
        fout << muchie.first << ' ' << muchie.second << '\n';
}