#include <fstream>
#include <vector>
#include <queue>
#include <bitset>

using namespace std;

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

const int N = 2e5;
const int INF = 1e9;

struct vecin
{
    int vf, cost;
};

int n,m,total;
vector<vecin> a[N+1];
vector <int> pred;

void prim(){
    vector<int>d(n+1);
    pred.resize(n+1);
    bitset<N+1> selectat;
    d[1]=0;
    for(int i=2;i<=n;i++)
        d[i]=INF;
    priority_queue<pair<int,int>> h;
    h.push({0,1});
    while(!h.empty())
    {
        int x=h.top().second;
        h.pop();
        if(selectat[x])
            continue;
        selectat[x]=1;
        total+=d[x];
        for(auto v:a[x])
        {
            int q=v.vf, p=v.cost;
            if(selectat[q])
                continue;
            if(p<d[q])
            {
                d[q]=p;
                pred[q]=x;
                h.push({-d[q],q});
            }
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        fin>>x>>y>>c;
        a[x].push_back({y,c});
        a[y].push_back({x,c});
    }
    prim();
    fout << total << '\n' << n - 1 << '\n';
    for (int i = 2; i <= n; i++)
    {
        fout << pred[i] << " " << i << '\n';
    }
    return 0;
}