#include <stdio.h>

#define INF 1000000000

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

int adj[200][200];
int next[200][200];

void warshall_floyd(int n) {
	int i, j, k;

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

void printPath(int s, int g) {
	for (; s != g; s = next[s][g])
		printf("%d ", s);
	printf("%d\n", g);
}

int main(void) {
	int i, j;
	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++) {
			adj[i][j] = i == j ? 0 : INF;
			next[i][j] = j;
		}

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

	warshall_floyd(n);
	printPath(s, g);

	return 0;
}