using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using Enu = System.Linq.Enumerable;

class Program
{
    static readonly int INF = (int)1e9;
    void CheckMin(ref int a, int b) { if (b < a) a = b; }

    void Solve()
    {
        int N = reader.Int(), NumE = reader.Int();
        int S = reader.Int(), G = reader.Int();
        int[,] dist = new int[N, N];
        var E = Enu.Range(0, N).Select(i => new List<Tuple<int, int>>()).ToArray();

        for (int a = 0; a < N; a++)
            for (int b = 0; b < a; b++)
                dist[a, b] = dist[b, a] = INF;
        for (int i = 0; i < NumE; i++)
        {
            int a = reader.Int(), b = reader.Int(), c = reader.Int();
            E[a].Add(Tuple.Create(b, c));
            E[b].Add(Tuple.Create(a, c));
            CheckMin(ref dist[a, b], c);
            CheckMin(ref dist[b, a], c);
        }
        for (int c = 0; c < N; c++)
            for (int a = 0; a < N; a++)
                for (int b = 0; b < N; b++)
                    dist[a, b] = Math.Min(dist[a, b], dist[a, c] + dist[c, b]);
        var ans = new List<int>();
        for (int at = S; ; )
        {
            ans.Add(at);
            if (at == G) break;
            E[at].Sort();
            foreach (var t in E[at])
            {
                int next = t.Item1, d = t.Item2;
                if (dist[at, G] == d + dist[next, G])
                {
                    at = next;
                    break;
                }
            }
        }

        Console.WriteLine(string.Join(" ", ans));
    }





    Reader reader = new Reader(Console.In);
    static void Main() { new Program().Solve(); }
}

class Reader
{
    private readonly TextReader reader;
    private readonly char[] separator = { ' ' };
    private readonly StringSplitOptions removeOp = StringSplitOptions.RemoveEmptyEntries;
    private string[] A = new string[0];
    private int i;

    public Reader(TextReader r) { reader = r; }
    public Reader(string file) { reader = new StreamReader(file); }
    public bool HasNext() { return Enqueue(); }
    public string String() { return Dequeue(); }
    public int Int() { return int.Parse(Dequeue()); }
    public long Long() { return long.Parse(Dequeue()); }
    public double Double() { return double.Parse(Dequeue()); }
    public int[] IntLine() { var s = Line(); return s == "" ? new int[0] : Array.ConvertAll(Split(s), int.Parse); }
    public int[] IntArray(int N) { return Enu.Range(0, N).Select(i => Int()).ToArray(); }
    public int[][] IntGrid(int H) { return Enu.Range(0, H).Select(i => IntLine()).ToArray(); }
    public string[] StringArray(int N) { return Enu.Range(0, N).Select(i => Line()).ToArray(); }
    public string Line() { return reader.ReadLine().Trim(); }
    private string[] Split(string s) { return s.Split(separator, removeOp); }
    private bool Enqueue()
    {
        if (i < A.Length) return true;
        string line = reader.ReadLine();
        if (line == null) return false;
        if (line == "") return Enqueue();
        A = Split(line);
        i = 0;
        return true;
    }
    private string Dequeue() { Enqueue(); return A[i++]; }
}