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

template< class T1, class T2 >
int upmin( T1 &x, T2 v ){
  if( x > v ){
    x = v;
    return 1;
  }
  return 0;
}

signed main(){
  int N, M, S, G; cin >> N >> M >> S >> G;
  vector< vector< pair< int, int > > > E( N );
  for( int i = 0; i < M; ++i ){
    int a, b, c; cin >> a >> b >> c;
    E[ a ].emplace_back( b, c );
    E[ b ].emplace_back( a, c );
  }
  for( int i = 0; i < N; ++i )
    sort( E.begin(), E.end() );
  vector< int > dis( N, 0x3f3f3f3f );
  vector< int > pre( N, -1 );
  priority_queue< pair< int, int >, vector< pair< int, int > >, greater< pair< int, int > > > pq;
  pq.emplace( dis[ S ] = 0, S );
  while( not pq.empty() ){
    int d, u; tie( d, u ) = pq.top(); pq.pop();
    if( d != dis[ u ] ) continue;
    for( int i = 0; i < E[ u ].size(); ++i ){
      int v, w; tie( v, w ) = E[ u ][ i ];
      if( upmin( dis[ v ], dis[ u ] + w ) )
        pre[ v ] = u,
        pq.emplace( dis[ v ], v );
    }
  }
  stack< int > ans;
  for( int u = G; u != -1; u = pre[ u ] )
    ans.emplace( u );
  for( ; not ans.empty(); ans.pop() )
    cout << ans.top() << " \n"[ ans.size() == 1 ];
  return 0;
}