#include <fstream>
#include <vector>
#include <queue>
#define inf 2147483647
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
int d[400001],tata[400001];
int n,m,x,y,c,Min,s;
bool viz[400001];
struct cmp
{
    bool operator ()(const int &a, const int &b)
    {
        return d[a]>d[b];
    }
};
vector <pair <int, int > > g[400001];
priority_queue < int , vector <int>  ,cmp > h;
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        g[x].push_back(make_pair(y,c));
        g[y].push_back(make_pair(x,c));
    }
    for(int i=2;i<=n;i++)
        d[i]=inf;
    h.push(1);
    while(!h.empty())
    {

        int nod=h.top();
        h.pop();
        if(viz[nod]==1)
            continue;
        s+=d[nod];
        viz[nod]=1;
        for(int j=0;j<g[nod].size();j++)
        {
            int v=g[nod][j].first;
            int c=g[nod][j].second;
            if(viz[v]==0&&d[v]>c)
            {
                d[v]=c;
                tata[v]=nod;
                h.push(v);
            }
        }
    }
    fout<<s<<'\n'<<n-1<<'\n';
    for(int i=2;i<=n;i++)
        fout<<tata[i]<<' '<<i<<'\n';
    return 0;
}