#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");

int E, V, v[100005], cnt;
vector<pair<pair<int, int>, int>> edges;

bool cmp(pair<pair<int, int>, int> a, pair<pair<int, int>, int> b){
    return a.second < b.second;
}

int main(){
    f >> V >> E;
    for(int i = 1; i <= E; i++){
        int x, y, c;
        f >> x >> y >> c;
        edges.push_back({{x, y}, c});
    }

    sort(edges.begin(), edges.end(), cmp);

    for(int i = 0; i < edges.size() && cnt < V - 1; i++){
        pair<int, int> u = edges[i].first;
        if(v[u.first] * v[u.second] == 0){
            cnt++;
            g << u.first << ' ' << u.second << '\n';
        }
    }
}