import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.PriorityQueue;
import java.util.Queue;
public class Main {
	public static int[][] cost;
	public static int n;
	public static int inf;
	public static boolean[][] check;
	public static void main(String[] args) throws NumberFormatException, IOException{
		ContestScanner in = new ContestScanner();
		n = in.nextInt();
		int m = in.nextInt();
		int s = in.nextInt();
		int g = in.nextInt();
//		Node[] node = new Node[n];
		inf = 10000000;
		check = new boolean[n][n];
		cost = new int[n][n];
//		for(int i=0; i<n; i++){
//			node[i] = new Node(i);
//		}
		for(int i=0; i<n; i++){
			for(int j=0; j<n; j++){
				if(i != j) cost[i][j] = inf;
			}
		}
		for(int i=0; i<m; i++){
			int a = in.nextInt();
			int b = in.nextInt();
			int c = in.nextInt();
//			node[a].createEdge(node[b]);
//			node[b].createEdge(node[a]);
			cost[a][b] = c;
			cost[b][a] = c;
			check[a][b] = true;
			check[b][a] = true;
		}
		
//		Queue<Node> qu = new PriorityQueue<Node>();
//		node[s].sum = 0;
//		checked[s] = true;
//		qu.add(node[s]);
//		while(!qu.isEmpty()){
//			Node nd = qu.poll();
//			
//		}
		for(int i=0; i<n; i++){
			for(int j=0; j<n; j++){
				for(int k=0; k<n; k++){
					if(cost[i][j] > cost[i][k]+cost[k][j]){
						cost[i][j] = cost[i][k]+cost[k][j];
					}
				}
			}
		}
		System.out.print(s+" ");
		dfs(s, s, g);
		System.out.println();
//		for(int i=0; i<n; i++){
//			for(int j=0; j<n; j++){
//				System.out.print(cost[i][j]+" ");
//			}
//			System.out.println();
//		}
	}
	
	public static void dfs(int s, int now, int g){
		if(now == g){
			return;
		}
		int min = inf;
		int minid = 0;
		for(int i=0; i<n; i++){
			if(i == now) continue;
			if(!check[i][now]) continue;
			if(min > cost[now][i]+cost[i][g]){
				minid = i;
				min = cost[now][i]+cost[i][g];
			}
		}
		System.out.print(minid+" ");
		dfs(s, minid, g);
	}
}


class MyComp implements Comparator<int[]>{
	public int compare(int[] a, int[] b) {
		return a[0] - b[0];
	}
}

class Reverse implements Comparator<Integer>{
	public int compare(Integer arg0, Integer arg1) {
		return arg1 - arg0;
	}
}

class Node implements Comparable<Node>{
	int id;
	List<Node> edge = new ArrayList<Node>();
//	List<Integer> cost = new ArrayList<Integer>();
	int sum;
	public Node(int id){
		this.id = id;
		sum = 100000000;
	}
	public void createEdge(Node node){
		edge.add(node);
//		cost.add(c);
	}
	@Override
	public int compareTo(Node o) {
		// TODO 自動生成されたメソッド・スタブ
		return sum - o.sum;
	}
}

class ContestWriter{
	private PrintWriter out;
	public ContestWriter(String filename) throws IOException{
		out = new PrintWriter(new BufferedWriter(new FileWriter(filename)));
	}
	
	public ContestWriter() throws IOException{
		out = new PrintWriter(System.out);
	}
	
	public void println(String str){
		out.println(str);
	}
	
	public void print(String str){
		out.print(str);
	}
	
	public void close(){
		out.close();
	}
}

class ContestScanner{
	private BufferedReader reader;
	private String[] line;
	private int idx;
	public ContestScanner() throws FileNotFoundException{
		reader = new BufferedReader(new InputStreamReader(System.in));
	}

	public ContestScanner(String filename) throws FileNotFoundException{
		reader = new BufferedReader(new InputStreamReader(new FileInputStream(filename)));
	}
	
	public String nextToken() throws IOException{
		if(line == null || line.length <= idx){
			line = reader.readLine().trim().split(" ");
			idx = 0;
		}
		return line[idx++];
	}
	public long nextLong() throws IOException, NumberFormatException{
		return Long.parseLong(nextToken());
	}
	public int nextInt() throws NumberFormatException, IOException{
		return (int)nextLong();
	}
	public double nextDouble() throws NumberFormatException, IOException{
		return Double.parseDouble(nextToken());
	}
}