#include <bits/stdc++.h>
#define F first
#define S second

using namespace std;

typedef struct {
  int to, cost;
} Edge;

typedef pair <long long, long long> P;
priority_queue <P> que;

long long n, m, a, b, st, go, c, node[222];

vector <Edge> G[222];

int main()
{
  cin >> n >> m >> st >> go;

  // グラフ入力
  for (int i = 0; i < m; i++) {
    cin >> a >> b >> c;

    G[a].push_back((Edge){b, c});
    G[b].push_back((Edge){a, c});
  }

  // node初期化
  for (int i = 0; i < n; i++) {
    node[i] = 1 << 30;
  }

  // ダイク
  node[go] = 0;
  que.push(P(go, 0));

  while (!que.empty()) {
    P p = que.top();
    que.pop();
    int v = p.F;
    
    if (node[v] < p.S) {
      continue;
    }

    for (int i = 0; i < G[v].size(); i++) {
      Edge e = G[v][i];

      if (node[e.to] > node[v] + e.cost) {
	node[e.to] = node[v] + e.cost;
	que.push(P(e.to, node[e.to]));
      }
    }
  }

  // 経路復元
  long long now = st, next;

  while (now != go) {
    next = 1 << 30;
    cout << now << ' ';

    for (int i = 0; i < G[now].size(); i++) {
      Edge e = G[now][i];
      
      if (node[e.to] + e.cost == node[now]) {
	if (e.to < next) {
	  next = e.to;
	}
      }
    }
    now = next;
  }

  cout << go << endl;
}