#define _USE_MATH_DEFINES
 
#include <iostream>
#include <iomanip>
#include <sstream>
 
#include <algorithm>
#include <cmath>
 
#include <string>
//#include <array>
#include <list>
#include <queue>
#include <vector>
#include <complex>
#include <set>
#include <map>
 
/////////
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define P(p) cout<<(p)<<endl;
 
#define PII pair<int,int>
/////////
typedef long long LL;
typedef long double LD;
/////////
using namespace::std;
/////////
const int Vmax = 200;

int main(void){
    std::cin.tie(0); 
    std::ios::sync_with_stdio(false);
    std::cout << std::fixed;//
    //cout << setprecision(16);//
	
	int N,M,start,goal;
	cin>>N>>M>>start>>goal;
	int d[Vmax][Vmax];
	int cost[Vmax][Vmax];
	const int INF = (int)1e8/2;

	rep(i,Vmax)rep(j,Vmax){
		d[i][j] = INF;
		cost[i][j] = INF;
	}
	rep(i,N){
		d[i][i] = 0;
		cost[i][i] = 0;
	}
	
	int a,b,c;
	rep(i,M){
		cin>>a>>b>>c;
		d[a][b] = c;
		d[b][a] = c;
		cost[a][b] = c;
		cost[b][a] = c;
	}
	/*
	rep(i,N)rep(j,N)rep(k,N){
		d[j][k] = min( d[j][k],d[j][i]+d[i][k] );
	}
	*/
	int dist[Vmax];
	fill_n(dist, Vmax, INF);
	bool use[Vmax];
	fill_n(use, Vmax, false);

	priority_queue<PII, vector<PII>,greater<PII>> q;
	q.push( PII(0,goal) );
	PII temp;
	while( !q.empty() ){
		temp = q.top();q.pop();
		if( use[temp.second] == true ) continue;
		use[temp.second] = true;
		dist[temp.second] = temp.first;

		for(int i=0;i<N;++i){
			if( use[i] == true ) continue;
			q.push( PII(temp.first + cost[temp.second][i],i) );
		}
	}
	/////////
	int now;
	now = start;
	vector<int> ans;
	ans.push_back(now);
	bool flag=true;
	while(flag)
	{
		flag = false;
		rep(i,N){
			if( now == i)continue;
			if( cost[now][i]+dist[i] == dist[now] ){
				now = i;
				flag = true;
				ans.push_back(now);
				break;
			}
		}
	}
	//ans.push_back(goal);
	vector<int>::iterator it = ans.begin();
	for(;it != ans.end() ;++it){
		cout << *it;
		if(it+1 != ans.end()){
			cout<<" ";
		}else{
			cout << '\n';
		}
	}
	
	return 0;
}