#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

struct Node {
  int v;
  int parent;
  ll cost;

  Node(int v = -1, int parent = -1, ll cost = -1) {
    this->v = v;
    this->parent = parent;
    this->cost = cost;
  }

  bool operator>(const Node &n) const {
    return cost > n.cost;
  }
};

struct Edge {
  int u;
  ll cost;

  Edge(int u, ll cost) {
    this->u = u;
    this->cost = cost;
  }
};

vector<Edge> E[210];

int main() {
  int N, M, S, G;
  cin >> N >> M >> S >> G;

  for (int i = 0; i < M; ++i) {
    int a, b, c;
    cin >> a >> b >> c;
    E[a].push_back(Edge(b, c));
    E[b].push_back(Edge(a, c));
  }

  vector<ll> dist(N + 1, LLONG_MAX);
  priority_queue <Node, vector<Node>, greater<Node>> pque;
  pque.push(Node(G, -1, 0));

  while (not pque.empty()) {
    Node node = pque.top();
    pque.pop();

    if (dist[node.v] <= node.cost) continue;
    dist[node.v] = node.cost;

    for (auto e : E[node.v]) {
      ll ncost = node.cost + e.cost;
      pque.push(Node(e.u, node.v, ncost));
    }
  }

  vector<int> ans;
  int cur = S;
  ans.push_back(cur);
  while (true) {
    int next = 1 << 29;
    for (Edge &e : E[cur]) {
      if (dist[cur] == dist[e.u] + e.cost) {
        next = min(next, e.u);
      }
    }
    cur = next;
    ans.push_back(cur);
    if (cur == G) break;
  }

  for (int v : ans) {
    cout << v;
    if (v != ans.back()) cout << " ";
  }
  cout << endl;

  return 0;
}