#include <bits/stdc++.h>
using namespace std;

#define each(i, c) for (auto& i : c)
#define mkp(a, b) make_pair(a, b)

typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> Pll;
const ll MOD = 1e9+7;

template<typename P, typename Q> ostream& operator << (ostream& os, pair<P, Q> p) { os << "(" << p.first << ": " << p.second << ")"; return os; }
template<typename T> ostream& operator << (ostream& os, vector<T> v) { os << "("; each (i, v) os << i << ", "; os << ")"; return os; }
template<typename K, typename V> ostream& operator << (ostream& os, map<K, V> m) { os << "{"; each (i, m) os << i << ", "; os << "}"; return os; }

typedef struct edge {
  ll to;
  ll cost;
} edge;
typedef vector<vector<edge>> G; // graph
typedef vector<Pll> GR; // graph result (cost, vertex num)

GR dijkstra(G &g, ll s) { // O(ElogV)
  priority_queue<Pll, vector<Pll>, greater<Pll>> q;
  GR res(g.size(), mkp(1e18, 0));
  
  res[s] = mkp(0, s);
  q.push(res[s]);

  while (!q.empty()) {
    auto p = q.top();
    q.pop();

    ll cost = p.first;
    ll pos = p.second;
    if (res[pos].first < cost) continue;

    each (j, g[pos]) {
      ll to = j.to;
      ll to_cost = j.cost + cost;
      if (to_cost >= res[to].first) continue;
      res[to].first = to_cost;
      q.push(mkp(to_cost, to));
    }
  }
  return res;
}

vector<ll> dijkstra_restore_path(G &g, GR &res, ll s, ll e) {
  ll from = e;
  vector<ll> path = {from};
  while (from != s) {
    ll to = 1e18;
    each (i, g[from]) {
      if (res[from].first == res[i.to].first + i.cost) {
        to = min(to, i.to);
      }
    }
    from = to;
    path.push_back(from);
  }
  reverse(path.begin(), path.end());
  return path;
}

int main() {
  ll n, m, s, g;
  cin >> n >> m >> s >> g;

  G graph(n);
  for (ll i = 0; i < m; ++i) {
    ll a, b, c;
    cin >> a >> b >> c;

    graph[a].push_back(edge{.to = b, .cost = c});
    graph[b].push_back(edge{.to = a, .cost = c});
  }

  auto res = dijkstra(graph, s);
  auto ans = dijkstra_restore_path(graph, res, s, g);

  for (ll i = 0; i < ans.size(); ++i) {
    cout << ans[i];
    if (i == ans.size()-1) cout << endl;
    else cout << " ";
  }

  return 0;
}