import java.io.PrintStream;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Queue;
import java.util.Scanner;

/**
 * Solution to Rainbow Roads
 * 
 * @author vanb
 */
public class rainbow_bfs_vanb
{
    private static Scanner sc;
    private static PrintStream ps;
    
    private class Road
    {
        public Intersection source, destination;
        public int color;
        public boolean visited;
        
        public Road( Intersection source, Intersection destination, int color )
        {
            this.source = source;
            this.destination = destination;
            this.color = color;
            this.visited = false;
        }
        
        public String toString()
        {
            return "[src:" + source.index + " dst:" + destination.index + "]";
        }
    }
    
    private int count;

    private class Intersection
    {
        public boolean eliminated = false;
        public List<Road> roads = new ArrayList<Road>(); 
        public int index;
        
        public Intersection( int index )
        {
            this.index = index;
        }      
    }
    
    private void doit()
    {
        int n = sc.nextInt();
        
        Intersection intersections[] = new Intersection[n];

        for( int i=0; i<n; i++ ) intersections[i] = new Intersection( i+1 );
        for( int i=0; i<n-1; i++ )
        {
            int a = sc.nextInt()-1;
            int b = sc.nextInt()-1;
            int c = sc.nextInt();
            
            intersections[a].roads.add( new Road( intersections[a], intersections[b], c ) );
            intersections[b].roads.add( new Road( intersections[b], intersections[a], c ) );
        }
        
        count = n;
        int colors[] = new int[n+1]; 
        Queue<Road> q = new ArrayDeque<Road>(n);
        for( Intersection intersection : intersections )
        {
            Arrays.fill( colors, 0 );
            
            for( Road road : intersection.roads ) ++colors[road.color];   
            
            q.clear();
            for( Road road : intersection.roads ) if( colors[road.color]>1 && !road.visited )
            {
                q.add( road );
            }
            
            while( !q.isEmpty() )
            {
                Road road = q.poll();
                road.visited = true;
                if( !road.destination.eliminated )
                {
                    road.destination.eliminated = true;
                    --count;
                }
                
                for( Road nextroad : road.destination.roads ) if( !nextroad.visited && nextroad.destination!=road.source )
                {
                    q.add( nextroad );    
                }
            }
            
        }
                
        ps.println( count );
        for( Intersection intersection : intersections ) if( !intersection.eliminated )
        {
            ps.println( intersection.index );
        }
    }
        
    public static void main( String[] args ) throws Exception
    {
        sc = new Scanner( System.in );
        ps = System.out;
        
        new rainbow_bfs_vanb().doit();
        //System.exit( 0 );
    }

}