#include<fstream>
#include<vector>

using namespace std;

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

struct nod
{
    int v,l;
};

const int N = 200001;
const int INF = 1001;

int n,m,nh;
int d[N], poz[N], pred[N],h[N];
bool t[N];
vector<nod> a[N];

void schimba(int nx, int ny);
void adauga(int nx);
void sterge(int i);
void urca(int i);
void coboara(int i);


void schimba(int nx, int ny)
{
    int aux = h[nx];
    h[nx] = h[ny];
    h[ny] = aux;
    poz[h[nx]] = nx;
    poz[h[ny]] = ny;
}

void adauga(int nx)
{
    h[++nh] = nx;
    poz[nx] = nh;
    urca(nh);
}

void sterge(int i)
{
    schimba(i, nh);
    nh--;
    coboara(i);
}

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

void coboara(int i)
{
    int fs = 2*i, fd = 2 * i + 1, bun = i;

    if(fs <= nh && d[h[fs]] < d[h[bun]])
        bun = fs;
    if(fd <= nh && d[h[fd]] < d[h[bun]])
        bun = fd;
    if(i != bun)
    {
        schimba(i,bun);
        coboara(bun);
    }
}

void apm(int x)
{
    for(int i = 1; i<=n; i++)
        d[i] = INF;

    d[x] = 0;
    adauga(x);

    while(nh != 0)
    {
        x = h[1];
        sterge(1);
        t[x] = true;

        for(int i = 0; i < a[x].size(); i++)
        {
            int y = a[x][i].v;
            int c = a[x][i].l;

            if(!t[y] && c < d[y])
            {
                d[y] = c;
                pred[y] = x;

                if(poz[y] == 0)
                    adauga(y);
                else urca(poz[y]);
            }
        }
    }
}

void citire()
{
    f>>n>>m;
    int na, nb, l;
    for(int i = 1; i<=m; i++)
    {
        f >> na >> nb >> l;
        a[na].push_back((nod){nb, l});
        a[nb].push_back((nod){na, l});
    }
}

void afisare()
{
    int s = 0;
    for(int i = 1; i<=n; i++)
        s += d[i];

    g << s << '\n' << n-1 << '\n';

    for(int i = 2; i <= n; i++)
        g << pred[i] << ' ' << i << '\n';
}

int main()
{
    citire();
    apm(1);
    afisare();
    return 0;
}