using System;
using System.Collections;
using System.Collections.Generic;
 
class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		
		int[] prev=new int[N];
		for(int i=0;i<N;i++)prev[i]=-1;
		int[] Tot=new int[N];
		int Inf=(int)(1e9);
		for(int i=0;i<N;i++)Tot[i]=Inf;
		
		SkewHeap<Pair> SH =new SkewHeap<Pair>();
		Tot[S]=0;
		SH.Push(new Pair(S,0));
		bool[] used=new bool[N];
		
		while(SH.Count>0){
			Pair p = SH.Top; SH.Pop();
			if(used[p.Pos])continue;
			used[p.Pos]=true;
			foreach (Pair e in E[p.Pos]) {
				if (Tot[e.Pos] > p.Cost + e.Cost) {
					Tot[e.Pos] = p.Cost + e.Cost;
					prev[e.Pos]=p.Pos;
					SH.Push(new Pair(e.Pos, Tot[e.Pos]));
				}
			}
		}
		
		List<int> L=new List<int>();
		int now=G;
		while(now!=S){
			L.Add(now);
			now=prev[now];
		}
		L.Add(now);
		
		var AA=L.ToArray();
		Array.Reverse(AA);
		Console.WriteLine(String.Join(" ",AA));
		
	}
	int N,M;
	int S,G;
	List<Pair>[] E;
	
	public Sol(){
		var d=ria();
		N=d[0];M=d[1];S=d[2];G=d[3];
		E=new List<Pair>[N];
		for(int i=0;i<N;i++)E[i]=new List<Pair>();
		
		for(int i=0;i<M;i++){
			var dd=ria();
			E[dd[0]].Add(new Pair(dd[1],dd[2]));
			E[dd[1]].Add(new Pair(dd[0],dd[2]));
		}
		for(int i=0;i<N;i++){
			E[i].Sort((x,y)=>x.Pos>y.Pos?1:x.Pos<y.Pos?-1:0);
		}
	}

	


	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(){return Console.ReadLine().Split(' ');}
	static int[] ria(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>int.Parse(e));}
	static long[] rla(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>long.Parse(e));}
	static double[] rda(){return Array.ConvertAll(Console.ReadLine().Split(' '),e=>double.Parse(e));}
}

class Pair : IComparable<Pair> {
	public int Pos;
	public int Cost;
	public Pair(int p, int c) {
		Pos = p; Cost = c;
	}
	public int CompareTo(Pair t) {
		//return this.Cost > t.Cost ? -1 : this.Cost < t.Cost ? 1 : 0;
		return this.Cost > t.Cost ? 1 : this.Cost < t.Cost ? -1 : 0;
	}
}


class SkewHeap<T> where T:IComparable<T>{
	public int Count{
		get{return cnt;}
		private set{cnt=value;}
	}
	
	public SkewHeap(){
		root=null;
		this.Count=0;
	}
	
	public void Push(T v){
		NodeSH<T> p=new NodeSH<T>(v);
		root=NodeSH<T>.Meld(root,p);
		this.Count++;
	}
	
	public void Pop(){
		if(root==null)return;
		root=NodeSH<T>.Meld(root.L,root.R);
		this.Count--;
	}
	
	public T Top{
		get{return root.Val;}
	}
	
	int cnt;
	NodeSH<T> root;
	
	class NodeSH<S> where S : IComparable<S> {
		public NodeSH<S> L, R;
		public S Val;

		public NodeSH(S v){
			Val = v;
			L = null; R = null;
		}
		public static NodeSH<S> Meld(NodeSH<S> a, NodeSH<S> b){
			if(a == null)return b;
			if (b == null) return a;
			if (a.Val.CompareTo(b.Val) > 0) swap(ref a, ref b);
			a.R = Meld(a.R, b);
			swap(ref a.L, ref a.R);
			return a;
		}

		static void swap<U>(ref U x, ref U y) {
			U t = x; x = y; y = t;
		}
	}
}