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

const int NMAX=200001;
vector <pair<int,int>> graf[NMAX];
int d[NMAX];
int parent[NMAX];
bool visited[NMAX];
priority_queue<pair<int,int>>h;

int main()
{

    int n,m;
    in>>n>>m;
    int x,y,cost;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y>>cost;
        graf[x].push_back(make_pair(y,cost));
        graf[y].push_back(make_pair(x,cost));
    }
    for(int i=1; i<=n; i++)
    {
        d[i]=INT_MAX;
        parent[i]=-1;
    }
    //pereche cost-nod
    h.push(make_pair(0,1));
    d[1]=0;
    while(h.empty()==0)
    {
        while(h.empty()==0 && visited[h.top().second]==1)
        {
            h.pop();
        }
        if(h.empty()==1)
        {
            break;
        }
        x=h.top().second;
        visited[x]=1;
        for(unsigned int i=0; i<graf[x].size(); i++)
        {
            y=graf[x][i].first;
            cost=graf[x][i].second;
            if(d[y]>cost && visited[y]==0)
            {
                d[y]=cost;
                h.push(make_pair(-d[y],y));
                parent[y]=x;
            }

        }
    }
    int cost_min=0;
    for(int i=1; i<=n; i++)
        {
            if(parent[i]!=-1)
                cost_min+=d[i];
        }
    out<<cost_min<<"\n";
    out<<n-1<<'\n';
    for(int i=1; i<=n; i++)
    {
        if(parent[i]!=-1)
            out<<i<<" "<<parent[i]<<'\n';
    }
    return 0;
}