#include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define pb(a) push_back(a)
#define pr(a) cout<<(a)<<endl
#define PR(a,b) cout<<(a)<<" "<<(b)<<endl
#define R cin>>
#define F first
#define S second
#define ll long long
bool check(int n,int m,int x,int y){return (x<0||x>=n||y<0||y>=m)?false:true;}
const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
typedef pair<int,int> P;

int main() {
  int n,m,s,g;
  cin >> n >> m >> s >> g;
  vector<P> v[n];
  rep(i,m) {
    int x,y,z;
    cin >> x >> y >> z;
    v[x].pb(P(y,z));
    v[y].pb(P(x,z));
  }
  rep(i,n) sort(all(v[i]));
  int d[n],p[n];
  fill(d,d+n,MAX);
  priority_queue<P,vector<P>,greater<P> > que;
  p[s]=-1;
  d[s]=0;
  que.push(P(0,s));
  while(!que.empty()) {
    P pp=que.top();que.pop();
    int now=pp.S,cost=pp.F;
    if(now==g) break;
    if(cost>d[now]) continue;
    rep(i,v[now].size()) {
      if(d[v[now][i].F]>d[now]+v[now][i].S) {
	d[v[now][i].F]=d[now]+v[now][i].S;
	p[v[now][i].F]=now;
	que.push(P(d[v[now][i].F],v[now][i].F));
      }
    }
  }
  vector<int> ans;
  while(g!=-1) {
    ans.pb(g);
    g=p[g];
  }
  rrep(i,ans.size()) {
    cout << ans[i];
    if(i) cout << " ";
  }
  cout << endl;
  return 0;
}