#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
#include <bitset>
#include <tuple>
using namespace std;

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

const int Inf = 0x3f3f3f3f, MaxN = 200001;

struct Edge{
    Edge() : node{0}, key{0}
    {}

    Edge(int node, int key) : node{node}, key{key}
    {}

    bool operator < (const Edge& e) const
    {
        return key > e.key;
    }

    int node, key;
};

int n;
bitset<MaxN> v;  //v[x] = 1, daca nodul x e vizitat, altfel v[x] = 0
vector<vector<pair<int, int>>> G;
vector<pair<int, int>> apm;
vector<int> key, t;
long long cost_apm;

void ReadData();
void Prim(int x);
void WriteAPM();

int main()
{
    ReadData();
    Prim(1);
    WriteAPM();
}

void ReadData()
{
    int x, y, w, m;
    fin >> n >> m;
    G = vector<vector<pair<int, int>>>(n + 1);
    while (m--)
    {
        fin >> x >> y >> w;
        G[x].emplace_back(y, w);
        G[y].emplace_back(x, w);
    }
}

void Prim(int x)
{
    priority_queue<Edge> Q;
    key = vector<int>(n + 1, Inf);
    t = vector<int>(n + 1);  //retine APM
    int y, ky; // ky = cheia lui y
    key[x] = 0;
    Q.emplace(x, 0);
    while (!Q.empty())
    {
        x = Q.top().node;
        v[x] = 1;  //true pentru bitset
        for (auto &p : G[x])
        {
            tie(y, ky) = p;
            if (v[y])
                continue;
            if (key[y] > ky)
            {
                key[y] = ky;
                t[y] = x;
                Q.emplace(y, ky);
            }
        }
        apm.emplace_back(x, t[x]);
        cost_apm += key[x];
        while(!Q.empty() && v[Q.top().node])
            Q.pop();
    }
}

void WriteAPM()
{
    fout << cost_apm << '\n' << n - 1 << '\n';
    for (size_t i = 1; i <= n; ++i)
        fout << apm[i].first << ' ' << apm[i].second << '\n';
}