import java.util.*;
import java.math.*;

public class Main {
    static int[] base;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int s = sc.nextInt();
        int g = sc.nextInt();
        ArrayList<Path>[] graph = new ArrayList[n];
        for (int i = 0; i < n; i++) {
            graph[i] = new ArrayList<Path>();
        }
        for (int i = 0; i < m; i++) {
            int a = sc.nextInt();
            int b = sc.nextInt();
            int c = sc.nextInt();
            graph[a].add(new Path(b, c));
            graph[b].add(new Path(a, c));
        }
        PriorityQueue<Route> queue = new PriorityQueue<>();
        ArrayList<Integer> list = new ArrayList<>();
        list.add(s);
        queue.add(new Route(s, 0, list));
        Route[] routes = new Route[n];
        while (queue.size() > 0) {
            Route r = queue.poll();
            if (routes[r.to] != null) {
                continue;
            }
            routes[r.to] = r;
            for (Path p : graph[r.to]) {
                ArrayList<Integer> newList = new ArrayList<>(r.name);
                newList.add(p.to);
                queue.add(new Route(p.to, r.score + p.score, newList));
            }
        }
        StringBuilder sbr = new StringBuilder();
        for (int i = 0; i < routes[g].name.size(); i++) {
            if (i != 0) {
                sbr.append(" ");
            }
            sbr.append(routes[g].name.get(i));
        }
        System.out.println(sbr);
    }
    
    static class Route implements Comparable<Route> {
        int to;
        int score;
        ArrayList<Integer> name;
        
        public Route (int to, int score, ArrayList<Integer> name) {
            this.to = to;
            this.score = score;
            this.name = name;
        }
        
        public int compareTo(Route another) {
            if (score == another.score) {
                for (int i = 0; i < name.size() && i < another.name.size(); i++) {
                    if (name.get(i) != another.name.get(i)) {
                        return name.get(i) - another.name.get(i);
                    }
                }
                return name.size() - another.name.size();
            } else {
                return score - another.score;
            }
        }
        
    }
    
    static class Path {
        int to;
        int score;
        public Path(int to, int score) {
            this.to = to;
            this.score = score;
        }
    }
}