#include <fstream>
#include <bits/stdc++.h>

using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
int n, m, i, j, x, y, z, sum, parent[200005], dist[200005];
bool viz[200005];
struct node
{
    int nod, cost;
}p, p2;
struct comparecost
{
    bool operator() (const node&a, const node&b)
    {
        return a.cost>b.cost;
    }
};
vector <node> v[200005];
priority_queue <node, vector<node>, comparecost>q;
int main()
{
    fin>>n>>m;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y>>z;
        v[x].push_back({y, z});
        v[y].push_back({x, z});
    }
    for(i=1; i<=n; i++)
        dist[i]=1e9;
    q.push({1, 0});
    dist[1]=0;
    while(!q.empty())
    {
        p=q.top();
        viz[p.nod]=1;
        q.pop();
        for(auto i: v[p.nod])
        {
            p2=i;
            if(dist[p2.nod]>p2.cost && viz[p2.nod]==0)
            {
                if(dist[p2.nod]!=1e9)
                    sum-=dist[p2.nod];
                sum+=p2.cost;
                dist[p2.nod]=p2.cost;
                parent[p2.nod]=p.nod;
                q.push({p2.nod, dist[p2.nod]});
            }
        }
    }
    fout<<sum<<'\n';
    fout<<n-1<<'\n';
    for(i=2; i<=n; i++)
        fout<<parent[i]<<" "<<i<<'\n';
    return 0;
}