#include <stdio.h>

#define INF 1000000000

#define min(a, b) (((a) < (b)) ? (a) : (b))

int d[200][200], G[200][200];

void printPath(int n, int start, int goal) {
	int i;
	int cur;

	cur = start;
	while (cur != goal) {
		printf("%d ", cur);

		for (i = 0; i < n; i++)
			if (i != cur && G[cur][i] + d[i][goal] == d[cur][goal]) {
				cur = i;
				break;
			}
	}
	printf("%d\n", goal);
}


int main(void) {
	int i, j, k;
	int n, m, s, g;

	scanf("%d %d %d %d", &n, &m, &s, &g);

	for (i = 0; i < n; i++)
		for (j = 0; j < n; j++)
			d[i][j] = G[i][j] = (i == j ? 0 : INF);

	while (m--) {
		int a, b, c;
		scanf("%d %d %d", &a, &b, &c);
		d[a][b] = d[b][a] = G[a][b] = G[b][a] = c;
	}

	for (k = 0; k < n; k++)
		for (i = 0; i < n; i++)
			for (j = 0; j < n; j++)
				d[i][j] = min(d[i][j], d[i][k] + d[k][j]);

	printPath(n, s, g);

	return 0;
}