/* -*- coding: utf-8 -*-
 *
 * 160.cc: No.160 最短経路のうち辞書順最小 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 200;
const int INF = 1 << 30;

/* typedef */

typedef vector<int> vi;
typedef queue<int> qi;
typedef pair<int,int> pii;
typedef vector<pii> vpii;

/* global variables */

vpii nbrs[MAX_N];
vi pths[MAX_N];
int dists[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, m, st, gl;
  cin >> n >> m >> st >> gl;

  for (int i = 0; i < m; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    nbrs[a].push_back(pii(b, c));
    nbrs[b].push_back(pii(a, c));
  }

  for (int i = 0; i < n; i++) dists[i] = INF;
  dists[st] = 0;

  priority_queue<pii> q;
  q.push(pii(0, st));

  while (! q.empty()) {
    pii u = q.top(); q.pop();
    int ud = -u.first, ui = u.second;

    if (ui == gl) break;

    vpii &nbru = nbrs[ui];
    vi pthv(pths[ui]);
    
    for (vpii::iterator vit = nbru.begin(); vit != nbru.end(); vit++) {
      int vi = vit->first, vd = ud + vit->second;
      pthv.push_back(vi);
      if (dists[vi] > vd || (dists[vi] == vd && pths[vi] > pthv)) {
	dists[vi] = vd;
	pths[vi] = pthv;
	q.push(pii(-vd, vi));
      }
      pthv.pop_back();
    }
  }

  printf("%d", st);
  for (int i = 0; i < pths[gl].size(); i++)
    printf(" %d", pths[gl][i]);
  putchar('\n');

  return 0;
}