// URL: https://yukicoder.me/problems/no/160

import std.algorithm, std.array, std.container, std.math, std.range, std.typecons, std.string;

version(unittest) {} else
void main()
{
  int N, M, S, G; io.getV(N, M, S, G);

  auto g = GraphW!int(N);
  foreach (_; 0..M) {
    int a, b, c; io.getV(a, b, c);
    g.addEdgeB(a, b, c);
  }

  auto d = g.dijkstra(G).dist;

  auto r = [S], t = 0;
  while (r.back != G) {
    auto nt = t, nv = N;
    foreach (e; g[r.back]) {
      if (t+e.wt+d[e.dst] != d[S]) continue;
      if (e.dst < nv) {
        nt = e.wt;
        nv = e.dst;
      }
    }
    t += nt;
    r ~= nv;
  }

  io.put(r);
  
}

struct Graph
{
  alias Node = int;
  Node n;
  Node[][] g;
  alias g this;
  this(Node n) { this.n = n; g = new Node[][](n); }
  void addEdge(Node u, Node v) { g[u] ~= v; }
  void addEdgeB(Node u, Node v) { g[u] ~= v; g[v] ~= u; }
}

struct GraphW(W = int, W i = 10^^9)
{
  alias Node = int, Wt = W, inf = i;
  struct Edge { Node src, dst; Wt wt; alias cap = wt; }
  Node n;
  Edge[][] g;
  alias g this;
  this(Node n) { this.n = n; g = new Edge[][](n); }
  void addEdge(Node u, Node v, Wt w) { g[u] ~= Edge(u, v, w); }
  void addEdgeB(Node u, Node v, Wt w) { g[u] ~= Edge(u, v, w); g[v] ~= Edge(v, u, w); }
}

struct GraphM(W = int, W i = 10^^9)
{
  alias Node = int, Wt = W, inf = i;
  Node n;
  Wt[][] g;
  alias g this;
  this(int n) { this.n = n; g = new Wt[][](n, n); }
  static GraphM!(W, i) init(Node n)
  {
    auto g = GraphM!(W, i)(n);
    foreach (i; 0..n) { g[i][] = inf; g[i][i] = 0; }
    return g;
  }
}

struct Dijkstra(Graph)
{
  alias Node = Graph.Node, Wt = Graph.Wt, Edge = Graph.Edge;
  Graph g;
  alias g this;
  Wt[] dist;
  Node[] prev;

  this(Graph g, Node s)
  {
    this.g = g;
    auto sent = n;

    dist = new Wt[](n);
    dist[] = g.inf;
    dist[s] = 0;

    prev = new Node[](n);
    prev[] = sent;

    auto q = heapify!("a.wt>b.wt")(Array!Edge(Edge(sent, s, 0)));
    while (!q.empty) {
      auto e = q.front; q.removeFront();
      if (prev[e.dst] != sent) continue;
      prev[e.dst] = e.src;
      foreach (f; g[e.dst]) {
        auto w = e.wt+f.wt;
        if (dist[f.dst] > w) {
          dist[f.dst] = w;
          q.insert(Edge(f.src, f.dst, w));
        }
      }
    }
  }
}
Dijkstra!Graph dijkstra(Graph, Node)(Graph g, Node s)
{ return Dijkstra!Graph(g, s); }

auto io = IO!()();
import std.stdio;
struct IO(string floatFormat = "%.10f", string delimiter = " ", alias IN = stdin, alias OUT = stdout)
{
  import std.conv, std.format, std.meta, std.traits;
  alias assignable = hasAssignableElements;

  auto getV(T...)(ref T v) { foreach (ref w; v) get(w); }
  auto getA(T)(size_t n, ref T v) if (assignable!T) { v = new T(n); foreach (ref w; v) get(w); }
  auto getC(T...)(size_t n, ref T v) if (allSatisfy!(assignable, T))
  {
    foreach (ref w; v) w = new typeof(w)(n);
    foreach (i; 0..n) foreach (ref w; v) get(w[i]);
  }
  auto getM(T)(size_t r, size_t c, ref T v) if (assignable!T && assignable!(ElementType!T))
  {
    v = new T(r); foreach (ref w; v) getA(c, w);
  }

  auto put(bool flush = false, T...)(T v)
  {
    foreach (i, w; v) { putA(w); if (i < v.length-1) OUT.write(delimiter); }
    OUT.writeln;
    static if (flush) OUT.flush();
  }
  auto putB(S, T)(bool c, S t, T f) { if (c) put(t); else put(f); }
  auto putRaw(T...)(T v) { OUT.write(v); OUT.writeln; }

  private
  {
    dchar[] buf;
    auto sp = (new dchar[](0)).splitter;
    void nextLine() { IN.readln(buf); sp = buf.splitter; }
    auto get(T)(ref T v) { if (sp.empty) nextLine(); v = sp.front.to!T; sp.popFront(); }

    auto putR(T)(T v)
    {
      auto w = v;
      while (!w.empty) { putA(w.front); w.popFront(); if (!w.empty) OUT.write(delimiter); }
    }
    auto putA(T)(T v)
    {
      static if (isInputRange!T && !isSomeString!T) putR(v);
      else if (isFloatingPoint!T) OUT.write(format(floatFormat, v));
      else OUT.write(v);
    }
  }
}