#include "bits/stdc++.h"
using namespace std;

int main() {
	int N, M, S, G;
	cin >> N >> M >> S >> G;
	vector<vector<pair<int, int>>> es(N);
	for (int i = 0; i < M; i++)
	{
		int a, b, c;
		cin >> a >> b >> c;
		es[a].push_back(make_pair(b, c));
		es[b].push_back(make_pair(a, c));
	}

	int MAX = 99999999;

	vector<pair<int, int>> dp(N);

	for (int i = 0; i < N; i++)
	{
		dp[i] = make_pair(MAX, -1);
		sort(es[i].begin(), es[i].end());
	}
	dp[G] = make_pair(0, -1);

	priority_queue<pair<pair<int, int>,int>> pq;
	pq.push(make_pair(make_pair(0, -1), G));
	while (!pq.empty()){
		auto now = pq.top(); pq.pop();
		int p = now.second;
		if (dp[p] < now.first) continue;
		for (auto to : es[p]){
			int p2 = to.first;
			auto next = make_pair(to.second + dp[p].first, p);
			if (dp[p2] > next){
				dp[p2] = next;
				pq.push(make_pair(next, p2));
			}
		}
	}

	string ans = to_string(S);
	while (S != G){
		S = dp[S].second;
		ans += " " + to_string(S);
	}
	cout << ans << endl;
}