#include <bits/stdc++.h>
using namespace std;
int main(){
	int n,m,s,g;	cin>>n>>m>>s>>g;
	vector<int> dp(n,(1<<25));
	vector<vector<int>> dist(n,vector<int>(n,(1<<25)));
	while(m--){
		int a,b,c;	cin>>a>>b>>c;
		dist[a][b]=dist[b][a]=c;
	}
	dp[g]=0;
	priority_queue<pair<int,int>> pq;
	pq.push(make_pair(0,g));
	while(!pq.empty()){
		auto now=pq.top();	pq.pop();
		int cost=-now.first,cur=now.second;
		if(cost>dp[cur])	continue;
		for(int i=0;i<n;i++){
			if(dist[cur][i]!=(1<<25)){
				if(cost+dist[cur][i]<dp[i]){
					dp[i]=cost+dist[cur][i];
					pq.push(make_pair(-dp[i],i));
				}
			}
		}
	}
	int cur=s;
	cout<<s;
	while(cur!=g){
		for(int i=0;i<n;i++){
			if(dist[i][cur]!=(1<<25)){
				if(dp[cur]==dp[i]+dist[i][cur]){
					cout<<" "<<i;
					cur=i;
					break;
				}
			}
		}
	}
	cout<<endl;
	return 0;
}