#include <iostream>
#include <utility>
#include <vector>
#include <algorithm>
using namespace std;
vector<int> parent;
struct edge{
	int from;
	int to;
	int weight;
	
	edge() : from(-1), to(-1), weight(-1){}
	edge(int from_, int to_, int weight_): from(from_), to(to_), weight(weight_){}
};
struct cmp{
	bool operator()(const edge& a, const edge& b){
		return a.weight < b.weight;
	}
};

int find(int x){
	if(parent[x] != x) parent[x] = find(parent[x]);
	return parent[x];
}
void merge(int x, int y){
	int rootX = find(x);
	int rootY = find(y);
	if(rootX != rootY) parent[rootY] = rootX;
	return;
}

int main(){
	//用adj的方式
	int n;
	cin >> n;
	//vector<vector<pair<int,int>>> adj(n, vector<pair<int,int>>());//可能没用 
	parent.resize(n);
	for(int i = 0; i < n; i++){
		parent[i] = i;
	} 
	
	vector<pair<int, int>> result(n, {-1, -1});
	int path = 0;
	int edge_num;
	cin >> edge_num;
	vector<edge> arr(edge_num);
	for(int i = 0; i < edge_num; i++){
		int a, b, w;
		cin >> a >> b >> w;	
		arr[i] = edge(a, b, w);//反着再来一遍就行 
	} 
	if(edge_num < n - 1) {
		cout << "Not Valid Full Graph" << endl;
		return ; 
	}

	sort(arr.begin(), arr.end(), cmp());
	for(auto x : arr){
		if(find(x.from) == find(x.to)){
			continue;
		}
		merge(x.from, x.to);
		result.push_back({x.from, x.to});
		path += x.weight;
	}
	cout << path << endl;
	for(auto x : result){
		if(x.first != -1 && x.second != -1) cout << "{" << x.first << ", " << x.second << "}" << " ";
	}
	cout << endl;
	return 0;
}