#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <climits>
using namespace std;
ifstream in("apm.in");
ofstream out("apm.out");
priority_queue<pair<int,int>,vector<pair<int,int>>, greater<>>q;
vector<pair<int,int>>graf[200005];
bool visited[200005];
int parent[200005];
int d[200005];
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({y,cost});
        graf[y].push_back({x,cost});
    }
    for(int i=1; i<=n; i++)
        {
            d[i]=INT_MAX;
            parent[i]=-1;

        }

    d[1]=0;
    q.push({0,1});
    while(!q.empty())
    {
         x=q.top().second;
         q.pop();
         visited[x]=1;


        for(unsigned i=0; i<graf[x].size(); i++)
        {
            y=graf[x][i].first;
            cost=graf[x][i].second;
            if(cost<d[y] && visited[y]==0)
            {
            d[y]=cost;
            q.push({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;
}