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
*/
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