#include <bits/stdc++.h>
#define syosu(x) fixed<<setprecision(x)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef pair<double,double> pdd;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<long double> vd;
typedef vector<vd> vvd;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<string> vs;
typedef vector<P> vp;
typedef vector<vp> vvp;
typedef vector<pll> vpll;
typedef pair<int,P> pip;
typedef vector<pip> vip;
const int inf=1<<29;
const ll INF=1ll<<60;
const double pi=acos(-1);
const double eps=1e-18;
const ll mod=1e9+7;
const int dx[4]={-1,0,1,0},dy[4]={0,-1,0,1};

int n,m,s,t;
vvi g;
vvp e;

int main(){
	cin>>n>>m>>s>>t;
	e=vvp(n);
	g=vvi(n,vi(n,inf));
	for(int i=0;i<m;i++){
		int u,v,c;
		cin>>u>>v>>c;
		g[u][v]=g[v][u]=c;
		e[u].push_back({v,c});
		e[v].push_back({u,c});
	}
	for(int i=0;i<n;i++) g[i][i]=0;
	for(int k=0;k<n;k++) for(int i=0;i<n;i++) for(int j=0;j<n;j++) g[i][j]=min(g[i][j],g[i][k]+g[k][j]);
	vi a(1,s);
	while(s!=t){
		P p={inf,0};
		for(auto q:e[s]){
			int v=q.first;
			if(v!=s) p=min(p,{g[v][t]+q.second,v});
		}
		s=p.second;
		a.push_back(s);
	}
	int N=a.size();
	for(int i=0;i<N;i++) cout<<a[i]<<" \n"[i==N-1];
}