#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

int main(){	
	
	int N,M,S,G;
	cin>>N>>M>>S>>G;
	
	vector<int> a(M),b(M),c(M);
	
	vector<vector<int>> E(N);
	
	rep(i,M){
		cin>>a[i]>>b[i]>>c[i];
		E[a[i]].push_back(i);
		E[b[i]].push_back(i);
	}
	vector<int> t = {};
	vector<pair<int,vector<int>>> dis(N,make_pair(Inf,t));
	
	priority_queue<pair<pair<int,vector<int>>,int>,vector<pair<pair<int,vector<int>>,int>>,greater<pair<pair<int,vector<int>>,int>>> Q;
	t.push_back(G);
	dis[G] = make_pair(0,t);
	Q.emplace(make_pair(0,t), G);
	
	while(Q.size()>0){
		auto p = Q.top().first;
		int u = Q.top().second;
		Q.pop();
		if(dis[u]!=p)continue;
		rep(i,E[u].size()){
			int v = u ^ a[E[u][i]] ^ b[E[u][i]];
			auto pp = p;
			pp.second.insert(pp.second.begin(),v);
			pp.first += c[E[u][i]];
			if(dis[v]>pp){
				dis[v] = pp;
				Q.emplace(pp,v);
			}
		}
		
	}
	
	auto ans = dis[S].second;
	rep(i,ans.size()){
		if(i!=0)cout<<' ';
		cout<<ans[i];
	}
	cout<<endl;
	
	return 0;
	
}