#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");

const int INF = 1e9;
const int nmax = 200000;
int n,m;
bool viz[nmax + 5];
int d[nmax + 5];
int t[nmax + 5];
int sum;
int solsz;
pair<int,int> sol[nmax*2 + 5];
vector <pair<int,int>> v[nmax + 5];
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> q;




int main()
{
    fin>>n>>m;
    for(int i=1; i<=n; i++)
        d[i] = INF;
    for(int i=1; i<=m; i++)
    {
        int x,y,c;
        fin>>x>>y>>c;
        v[x].push_back({c,y});
        v[y].push_back({c,x});
    }
    d[1]=0;
    q.push({0,1});
    while(!q.empty())
    {
        int mc = q.top().first;
        int nod = q.top().second;
        q.pop();
        if(viz[nod]) continue;
        viz[nod]=true;
        for(auto& i : v[nod])
            if(i.first < d[i.second] && !viz[i.second])
            {
                d[i.second] = i.first,t[i.second] = nod;
                q.push({i.first,i.second});
            }
    }
    for(int i=2;i<=n;i++)
        sum+=d[i];
    fout<<sum<<'\n';
    fout<<n-1<<'\n';
    for(int i=2;i<=n;i++)
        fout<<i<<' '<<t[i]<<'\n';

}