/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package mst;

/**
 *
 * @author Hp
 */
import java.io.File;
import java.io.FileNotFoundException;
import java.util.*;
class kru{
    int i,j,k,a,b,u,v,n,ne=1;
    int min,mincost=0;
      int cost[][]=new int[1000][1000];
      int parent[]=new int[1000];

      kru(int n,int e,Scanner sc){
    	for(i=1;i<=e;i++)
	{

                    int x=sc.nextInt();
                    int y=sc.nextInt();
                    int q=sc.nextInt();
                        cost[y][x]=cost[x][y]=q;

	}
        for(i=1;i<=n;i++)
        {
            for(int ji=1;ji<=n;ji++)
            {
                if(cost[i][ji]==0)
                    cost[i][ji]=999;
            }
        }

	while(ne < n)
	{
		for(i=1,min=999;i<=n;i++)
		{
			for(j=1;j <= n;j++)
			{
				if(cost[i][j] < min)
				{
					min=cost[i][j];
					a=u=i;
					b=v=j;
				}
			}
		}
		u=find(u);
		v=find(v);
		if(uni(u,v)!=0)
		{
                    System.out.println(a+" "+b);
                        ne++;
			mincost +=min;
		}
		cost[a][b]=cost[b][a]=999;
	}
        System.out.println("min_cost"+mincost);
      }
        int find(int i)
        {
	while(parent[i]!=0)
	i=parent[i];
	return i;
        }
        int uni(int i,int j)
        {
            if(i!=j)
            {
		parent[j]=i;
		return 1;
            }
	return 0;
        }

}
public class Mst {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws FileNotFoundException {
        // TODO code application logic here
        File file=new File("C:\\Users\\Student\\Desktop\\shosho\\mst-2015-10-03\\mst\\src\\mst\\input.txt");
         Scanner sc=new Scanner(file);
         int n=sc.nextInt();
           int e=sc.nextInt();
        kru m=new kru(n,e,sc);

    }

}