#include <stdio.h>

#define INF 1000000000

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

int d[200][200];
int next[200][200];

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

	for (cur = start; cur != goal; cur = next[cur][goal])
		printf("%d ", cur);
	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] = INF;

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

	for (i = 0; i < n; i++)
		for (j = 0; j < n; j++)
			next[i][j] = j;

	for (k = 0; k < n; k++)
		for (i = 0; i < n; i++)
			for (j = 0; j < n; j++)
				if (d[i][k] + d[k][j] < d[i][j]) {
					d[i][j] = d[i][k] + d[k][j];
					next[i][j] = next[i][k];
				} else if (d[i][k] + d[k][j] == d[i][j])
					next[i][j] = min(next[i][j], next[i][k]);

	printPath(s, g);

	return 0;
}