#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;

typedef struct{
	int to;
	int cost;
}edge;


//distance from s
//O(E log V)
void dijkstra(vector< vector<edge> > &G, vector<int> &dist, vector<int> &last, int s){

	//INF as distance
	const int INF = 1<<29;
	
	//first : distance from s, second : its vertex
	priority_queue< pair<int, int> , vector< pair<int, int>  >, greater< pair<int, int> >> pq;
	 
	fill(dist.begin(), dist.end(), INF);
	dist[s] = 0;
	last[s] = s;

	pq.push( {dist[s], s} );

	while(!pq.empty()){
		auto q = pq.top();
		pq.pop();

		int from = q.second;
		if(dist[from] < q.first) continue; // it's not minimum distance

		int n=G[from].size();
		for(int i=0; i<n; i++){
			edge& e = G[from][i];
			int next = dist[from] + e.cost;

			if(dist[e.to] == next){
				last[e.to] = min(last[e.to], from);
			}else if(dist[e.to] > next){
				dist[e.to] = next;
				last[e.to] = from;
				pq.push( {dist[e.to], e.to} );
			}
		}
	}
}
 
void add_edge(vector<vector<edge> > &G, int from, int to, int cost){
	G[from].push_back( (edge){to, cost} );
	G[to].push_back( (edge){from, cost} );
}
 
int main(){
	int N,M,S,G;
	cin >> N >> M >> S >> G;

	vector<vector<edge>> Graph(N);
	for(int i=0; i<M; i++){
		int a,b,c;
		cin >> a >> b >> c;

		add_edge(Graph, a, b, c);
	}

	vector<int> dist(N);
	vector<int> last(N, -1);
	dijkstra(Graph, dist, last, G);
	vector<int> ans;
	{
		for(int pos = S; pos != last[pos]; pos = last[pos]){
			ans.push_back(pos);
		}
		ans.push_back(G);
	}
	for(int i=0; i<ans.size(); i++){
		cout << ans[i] << " ";
	}
	cout << endl;

	return 0;
}