#include<bits/stdc++.h>
using namespace std;
const int INF = 1 << 30;
typedef pair< int, int > Pi;
struct edge
{
  int to, cost;
};
 
vector< edge > graph[10000];
int N, M, S, G;
 
int main()
{  
  scanf("%d %d %d %d", &N, &M, &S, &G);
  while(M--) {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    graph[a].push_back((edge){b, c});
    graph[b].push_back((edge){a, c});
  }
 
  priority_queue< Pi, vector< Pi >, greater< Pi > > que;
  que.emplace(0, G);
  vector< Pi > v(N, Pi(INF, INF));
  v[G] = {0, -1};
  while(!que.empty()) {
    auto p = que.top(); que.pop();
    for(auto& e : graph[p.second]) {
      if(Pi(p.first + e.cost, p.second) >= v[e.to]) continue;
      v[e.to] = Pi(p.first + e.cost, p.second);
      que.emplace(v[e.to].first, e.to);
    }
  }
 
  vector< int > dd;
  int now = S;
  dd.push_back(S);
  while(now != G) {
    int net  = 1 << 30;
    for(auto& k : graph[now]) {
      if(v[k.to].first + k.cost == v[now].first) net = min(net, k.to);
    }
    now = net;
    dd.push_back(now);
  }
  bool first = false;
  for(int i = 0; i < dd.size(); i++) {
    if(first++) putchar(' ');
    printf("%d", dd[i]);
  }
  putchar('\n');
}