/* cs2me3
 * Winter 2004
 * by Michael Soltys */

#include <stdio.h>
#define TRUE 1

typedef struct {
	int i;
	int j;
	int w;
} edge;

FILE *fpt;

void sort_by_weight(int E, edge *graph)
{
/* Sorts the edges of graph in non-decreasing order by weights. */
}

void spanning_tree(int N, int E, edge *graph)
{
/* Compute the spanning tree of graph where edges are assumed to be
 * already ordered by weights--unnecessary edges will get their
 * weights set to 0. */
}

main(int argc, char *argv[])
{
	int N; /* number of nodes */
	int E=0; /* number of edges */
	edge *graph; /* input graph */
	int flag=TRUE;
	int c=0;
	edge x;

	fpt = fopen(argv[1], "r");
	fscanf(fpt, "%d", &N);

	/* allocate memory for a graph of size at most (N*N) */
	graph=(edge *) malloc(N*N*sizeof(edge));

	while (flag) { 
		fscanf(fpt, "%d %d %d", &x.i, &x.j, &x.w);

		if (x.i==-1)
			break;

		graph[E]=x;
		E++;
	}

	fclose(fpt);

	sort_by_weight(E, graph);

	spanning_tree(N, E, graph);

	while (c<E) {
		if (graph[c].w!=0)
			printf("%d %d %d\n",graph[c].i,graph[c].j,graph[c].w);
		c++;
	}
}