#include <bits/stdc++.h>

using namespace std;

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

const int MAX = 200001;
const int INF = 2e9;
int h[MAX], poz[MAX], d[MAX], x, y, n, nh, cst[2*MAX], cost, urm[2*MAX], vf[2*MAX], lst[2*MAX], c, nr, pred[MAX], m;

void adauga(int x, int y, int c)
{
    vf[++nr] = y;
    urm[nr] = lst[x];
    lst[x] = nr;
    cst[nr] = c;
}

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 ad_in_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--);
    coboara(p);
}

void prim()
{
    for(int i = 2; i <= n; i++)
    {
        d[i] = INF;
    }
    for(int i = 1; i <= n; i++)
    {
        ad_in_heap(i);
    }
    d[1] = 0;
    while(nh > 0)
    {
        x = h[1];
        sterge(1);
        poz[x] = -1;
        cost += d[x];
        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;
    while(m--)
    {
        in >> x >> y >> c;
        adauga(x,y,c);
        adauga(y,x,c);
    }
    prim();
    out << cost << "\n" << n - 1 << "\n";
    for(int i = 2; i <= n; i++)
    {
        out << pred[i] << " " << i;
        out << "\n";
    }
    return 0;
}