#include <algorithm>
#include <climits>
#include <iostream>
#include <map>
#include <vector>

int N;
int M;
int S;
int G;
std::map<std::pair<int, int>, int> cost;
const int INF = 2000000;
std::vector<int> dist;
std::vector<bool> used;
std::vector<int> next;

int getCost(int u, int v)
{
	if (cost.find(std::pair<int, int>(u, v)) == cost.end()) {
		return INF;
	}
	return cost[std::pair<int, int>(u, v)];
}

void set_nmsg(int n, int m, int s, int g)
{
	N = n;
	M = m;
	S = s;
	G = g;
}

void set_abc(int a, int b, int c)
{
	cost[std::pair<int, int>(a, b)] = c;
	cost[std::pair<int, int>(b, a)] = c;
}

void resolve()
{
	dist.resize(N);
	used.resize(N);
	next.resize(N);

	std::fill(dist.begin(), dist.end(), INF);
	std::fill(used.begin(), used.end(), false);
	std::fill(next.begin(), next.end(), -1);
	dist[G] = 0;

	for (;;) {
		int v = -1;
		for (int u = 0; u < N; u++) {
			if (!used[u] && (v == -1 || dist[u] < dist[v])) v = u;
		}
		if (v == -1) break;
		used[v] = true;
		for (int u = 0; u < N; u++) {
			int nd = dist[v] + getCost(v, u);
			if (nd < dist[u] || (nd == dist[u] && v < next[u])) {
				next[u] = v;
				dist[u] = nd;
			}
		}
	}

	int p = S;
	while (p != G) {
		std::cout << p << " ";
		p = next[p];
	}
	std::cout << p << std::endl;
}

int main()
{
	std::cin >> N >> M >> S >> G;
	for (int i = 0; i < M; i++) {
		int a, b, c;
		std::cin >> a >> b >> c;
		set_abc(a, b, c);
	}
	resolve();
}