#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <tuple>
#include <utility>
using namespace std;

bool viz[200005];
vector <pair<int, int>> adj[200005];
vector <tuple<int, int, int >> muchii;

long long prim(int x)
{
    priority_queue<tuple<int, int, int >,vector<tuple<int, int, int >>,greater<tuple<int, int, int >> > heap;
    int y;
    long long Cost = 0;
    tuple<int, int, int >  tuplu;
    heap.push(make_tuple(0, x, x));
    while (!heap.empty())
    {

        tuplu = heap.top();
        heap.pop();
        x = get<1>(tuplu);
        y = get<2>(tuplu);

        if (viz[x] == true)
            continue;
        Cost += get<0>(tuplu);
        if (x != y)
            muchii.push_back(make_tuple(get<0>(tuplu), x, y));
        viz[x] = true;
        for (int i = 0; i < adj[x].size(); i++)
        {
            y = adj[x][i].second;
            if (viz[y] == false)
                heap.push(make_tuple(adj[x][i].first, y, x));
        }
    }
    return Cost;
}

int main()
{
    ifstream f("apm.in");
    ofstream g("apm.out");
    int i, N, M, x, y, c;

    f >> N >> M;
    for (i = 1; i <= M; i++)
    {
        f >> x >> y >> c;
        adj[x].push_back(make_pair(c, y));
        adj[y].push_back(make_pair(c, x));
    }

    g << prim(1) << "\n";
    int lim = muchii.size();
    g << lim << "\n";
    for (i = 0; i < lim; i++)
        g << get<1>(muchii[i]) << " " << get<2>(muchii[i]) << "\n";
    return 0;
}