#include <iostream>
#include <fstream>

using namespace std;

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

const int N = 200000, M = 400000, INF = 1 << 30;
int n, m, d[N], lst[N], vf[2*M], urm[2*M], pred[N], h[N], poz[N], nh, nr, cost, cst[2*M];

void schimb(int p, int q)
{
    swap(h[p], h[q]);
    poz[h[p]] = p;
    poz[h[q]] = q;
}

void urca(int p)
{
    while(p > 1 && d[h[p]] < d[h[p / 2]]){
        schimb(p, p / 2);
        p /= 2;
    }
}

void adauga_lista(int a, int b, int c)
{
    vf[++nr] = b;
    cst[nr] = c;
    urm[nr] = lst[a];
    lst[a] = nr;
    vf[++nr] = a;
    cst[nr] = c;
    urm[nr] = lst[b];
    lst[b] = nr;
}

void adauga_heap(int p)
{
    h[++nh] = p;
    poz[p] = nh;
    urca(nh);
}

void coboara(int p)
{
    int fs = 2 * p, fd = 2 * p + 1, bun = p;
    if(fs <= nh && d[h[fs]] < d[h[bun]]){
        bun = fs;
    }
    if(fd <= nh && d[h[fd]] < d[h[bun]]){
        bun = fd;
    }
    if(bun != p){
        schimb(bun, p);
        coboara(bun);
    }
}
void sterge(int p)
{
    schimb(p, nh--);
    urca(p);
    coboara(p);
}

void prim()
{
    int x, y, c;
    for(int i = 2; i <= n; i++){
        d[i] = INF;
        adauga_heap(i);
    }
    d[1] = 0;
    adauga_heap(1);
    //cout << "\n\n";
    while(nh > 0){
        x = h[1];
        //cout << pred[x] << "\t" << x << "\t" << d[x] << "\n";
        sterge(1);
        poz[x] = -1;
        cost += d[x];
        //cnt++;
        for(int p = lst[x]; p != 0; p = urm[p]){
            y = vf[p];
            c = cst[p];
            if(poz[y] != -1 && c < d[y]){
                d[y] = c;
                urca(poz[y]);
                pred[y] = x;
            }
        }
    }
}

int main()
{
    in >> n >> m;
    int x, y, z;
    for(int i = 1; i <= m; i++){
        in >> x >> y >> z;
        adauga_lista(x, y, z);
    }
    prim();
    out << cost << "\n" << n - 1 << "\n";
    for(int i = 2; i <= n; i++){
        out << pred[i] << " " << i << "\n";
    }

    return 0;
}