#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <fstream>
using namespace std;

const string file = "apm";

const string infile = file + ".in";
const string outfile = file + ".out";

const int INF = 0x3f3f3f3f;
int N, M;
vector<vector<pair<int, int> > > G;

vector<int> dist;
vector<int> prec;
vector<int> uz;
vector<pair<int, int> > edges;

int MinCost;

void Prim()
{
	priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > heap;
	heap.push(make_pair(0, 1));
	dist[1] = 0;

	while(heap.empty() == false)
	{
		int cost = heap.top().first;
		int c = heap.top().second;
		heap.pop();
		if(dist[c] != cost)
			continue;

		uz[c] = true;
		MinCost += cost;
		edges.push_back(make_pair(prec[c], c));

		for(vector<pair<int, int> >::iterator itr = G[c].begin();
			itr != G[c].end();
			itr++)
		{
			if(uz[itr->first] == false && dist[itr->first] > itr->second)
			{
				prec[itr->first] = c;
				dist[itr->first] = itr->second;
				heap.push(make_pair(dist[itr->first], itr->first));
			}
		}
	}

}

int main()
{
	fstream fin(infile.c_str(), ios::in);
	fin >> N >> M;
	G.resize(N + 1);

	dist.resize(N + 1, INF);
	prec.resize(N + 1);
	uz.resize(N + 1);
	for(int i = 0; i < M; i++)
	{
		int x, y, c;
		fin >> x >> y >> c;
		G[x].push_back(make_pair(y, c));
		G[y].push_back(make_pair(x, c));
	}
	fin.close();


	Prim();


	fstream fout(outfile.c_str(), ios::out);
	fout << MinCost << "\n";
	fout << edges.size() - 1 << "\n";
	for(vector<pair<int, int> > ::iterator itr = edges.begin() + 1;
		itr != edges.end();
		itr++)
	{
		fout << itr->first << " "<< itr->second << "\n";
	}
	fout.close();
}