#include <fstream>
#include <iostream>
#include <string>
#include <complex>
#include <cmath>
#include <set>
#include <vector>
#include <map>
#include <queue>
#include <cstdio>
#include <stack>
#include <algorithm>
#include <list>
#include <bitset>
#include <ctime>
#include <climits>
#include <cassert>
#include <iomanip>

using namespace std;


const string file = "apm";
const string inputF = file + ".in";
const string outputF = file + ".out";

const double epsilon = 1e-7;
#define LL long long
#define ULL unsigned long long 
#define MOD1 666013
#define MOD2 666019
#define MOD3 1999999973
#define base 73

typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<bool> vb;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<string> vs;
typedef pair<int, int> ii;
typedef pair<long long, long long> ll;
typedef vector<ii> vii;
typedef vector<ll> vll;

#define all(V) V.begin(), V.end()
#define allr(V) V.rbegin(), V.rend()
#define for_c_it(container, it) for (auto it : container)
#define present(container, element) (container.find(element) != container.end()) 
#define sz(a) int((a).size()) 
#define pb push_back 
#define mp make_pair
#define zeroes(x) ((x ^ (x - 1)) & x)
#define maxn 200001

vector <vii> graph;
vii apm;
vi dist, from, viz;
int N, M, ans;

int main() {
#ifndef INFOARENA
	freopen("input.txt", "r", stdin);
#else 
	freopen(inputF.c_str(), "r", stdin);
	freopen(outputF.c_str(), "w", stdout);
#endif
	int i, x, y, c;
	scanf("%d %d", &N, &M);
	dist.resize(N, INT_MAX);
	graph.resize(N);
	from.resize(N);
	viz.resize(N);
	
	for (i = 0; i < M; ++i) {
		scanf("%d %d %d", &x, &y, &c);
		--x; --y;
		graph[x].pb(mp(y, c));
		graph[y].pb(mp(x, c));
	}
	
	dist[0] = 0;
	priority_queue <ii, vii, greater<ii> > heap;
	ans = 0;
	
	int node, cost;
	for (auto to: graph[0]) {
		dist[to.first] = to.second;  
		heap.push(mp(to.second, to.first));
	}
	viz[0] = 1;
	while (!heap.empty()) {
		node = heap.top().second;
		cost = heap.top().first;
		heap.pop();
		if (cost > dist[node] || viz[node]) {
			continue;
		}
		ans += cost;
		viz[node] = 1;
		apm.pb(mp(node, from[node]));
		for (auto to:graph[node]) {
			if (to.first && !viz[to.first] && dist[to.first] > to.second) {
				dist[to.first] = to.second;
				from[to.first] = node;
				heap.push(mp(to.second, to.first));
			}
		}
	}
	
	printf("%d\n%d\n", ans, N - 1);
	for (auto pr: apm) {
		printf("%d %d\n", pr.first + 1, 1 + pr.second);
	}
	return 0;
}