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

using namespace std;

struct edge
{
    int u, v;
    int weight;

    // sort by weight and here we overload < operator.
    bool operator < (const edge &p) const {
        return weight < p.weight;
    }
};

vector <edge> e;

int main()
{
    int nodes, edges;

    cin >> nodes >> edges;
    for(int i = 0; i < edges; i++)
    {
        edge get;
        int u, v, weight;

        cin >> u >> v >> weight;

        get.u = u;
        get.v = v;
        get.weight = weight;

        e.push_back(get);
    }

    sort(e.begin(), e.end());

    for(int i = 0; i < edges; i++)
    {
        // to access the value of structure list
        // we can use vector_name[counter].member_name;
        cout <<"first_node: " << e[i].u << " second_node : "<< e[i].v;
        cout << " cost : " << e[i].weight << endl;
    }

    return 0;
}