package yukicoder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main{
	public static void main(String[] args)throws Exception{
		new Main().solve();
	}
	void solve(){
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt();
		int m=sc.nextInt();
		int s=sc.nextInt();
		int g=sc.nextInt();
		Dijkstra dj=new Dijkstra(n);
		for(int i=0;i<m;i++){
			int from=sc.nextInt();
			int to=sc.nextInt();
			int cost=sc.nextInt();
			dj.addEdge(from, to, cost);
		}
		int[] prv=dj.getShortestPath(s, g);
		String ans="";
		ans+=g;
		int f=g;
		while(true){
			int a=prv[f];
			f=a;
			if(a!=-1){
				ans=a+" "+ans;
				if(a==s)break;
			}
		}
		System.out.println(ans);
//		tr(prv);

	}
	void tr(Object...o){System.out.println(Arrays.deepToString(o));}
	class Dijkstra{
		int n;
		long[] d;
		int s;
		int[] prv;
		List<Edge>[]edges;
		PriorityQueue<Vertice> pq;
		final long INF=Long.MAX_VALUE/4;
		Dijkstra(int n){
			this.n=n;
			d=new long[n];
			prv=new int[n];
			Arrays.fill(prv, -1);
			@SuppressWarnings("unchecked")
			List<Edge>[]edges=new List[n];
			this.edges=edges;
			for(int i=0;i<n;i++){
				edges[i]=new ArrayList<Edge>();
			}
			s=-1;
		}
		int[] getShortestPath(int i,int j){
			if(i!=s){
				s=i;
				Arrays.fill(d, INF);
				d[i]=0;
				pq=new PriorityQueue<Vertice>();
				pq.add(new Vertice(i,d[i]));
				while(!pq.isEmpty()){
					Vertice u=pq.poll();
					if(d[u.me]<u.cost){
						continue;//skip old vertex
					}
					for(int ii=0;ii<edges[u.me].size();ii++){
						Edge e=edges[u.me].get(ii);
						if(d[e.from]!=INF&&e.cost+d[e.from]<d[e.to]){
							d[e.to]=e.cost+d[e.from];
							pq.add(new Vertice(e.to,d[e.to]));
							prv[e.to]=e.from;
						}
					}
				}
				s=i;
			}
			//			return d[j];
			return prv;
		}
		void addEdge(int from,int to,long cost){
			edges[from].add(new Edge(from,to,cost));
		}
	}
	class Edge{
		int from;
		int to;
		long cost;
		Edge(int i,int j,long cost){
			this.from=i;
			this.to=j;
			this.cost=cost;
		}
	}
	class Vertice implements Comparable<Vertice>{
		int me;
		long cost;
		Vertice(int me,long cost){
			this.me=me;
			this.cost=cost;
		}
		@Override
		public int compareTo(Vertice o){
			//			return Long.compare(this.cost, o.cost);
			return this.cost>o.cost?1:this.cost<o.cost?-1:this.me>o.me?1:this.me<o.me?-1:0;
		}
	}
}