import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static class Edge{
        int src,nbr,wt;
        Edge(int src,int nbr,int wt){
            this.src = src;
            this.nbr = nbr;
            this.wt = wt;
        }
    }
    public static void display(ArrayList<Edge>[] graph){
        int vtces = graph.length;
        for(int i = 0 ; i < vtces ; i++){
            ArrayList<Edge> list = graph[i];
            System.out.print(i+" -> ");
            for(Edge e : list){
                System.out.print(e.nbr+" ");
            }
            System.out.println();
        }
    }
    public static void main(String[] args) {
        Scanner  scn = new Scanner(System.in);

        int vtces = scn.nextInt();
        int edges = scn.nextInt();

        ArrayList<Edge>[] graph = new ArrayList[vtces];

        for(int i = 0 ; i < vtces ; i++){
            graph[i] = new ArrayList<Edge>();
        }

        for(int i = 0 ; i < edges ; i++){
            int v1 = scn.nextInt();
            int v2 = scn.nextInt();
            int wt = scn.nextInt();

            graph[v1].add(new Edge(v1,v2,wt));
            graph[v2].add(new Edge(v2,v1,wt));
        }

        display(graph);        
    }
}

/*
7
8
0 3 40
0 1 10
1 2 10
2 3 10
3 4 4
4 5 3
5 6 3
4 6 8
*/