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

struct Edge{
  int to,cost;
};

vector<Edge> e[201010];
int d[201010];
int pre[201010];

int main(){
  int n,m,s,g;
  cin>>n>>m>>s>>g;
  int u,v,c;
  for(int i=0;i<m;++i){
    cin>>u>>v>>c;
    e[v].push_back(Edge{u,c});
    e[u].push_back(Edge{v,c});
  }
  fill_n(d, 201010, 1e9+1);
  
  priority_queue<int, vector<int>, greater<int>> p_q;
  p_q.push(g);
  d[g] = 0;
  while(!p_q.empty()){
    int fr=p_q.top();p_q.pop();

    for(auto &&t: e[fr]){
      if (d[t.to] > d[fr] + t.cost) {
        d[t.to] = d[fr] + t.cost;
        pre[t.to] = fr;
        p_q.push(t.to);
      }
    }
  }

  /*
  for (int i=0;i<n;++i){
    cout << d[i] << endl;
    cout << pre[i] <<endl<<endl;
  }
  */

  while (g != s){
    cout << s << " ";
    s = pre[s];
  }
  cout << s << endl;
  
  return 0;
}