import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int start = sc.nextInt();
        int goal = sc.nextInt();
        ArrayList<TreeMap<Integer, Integer>> graph = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            graph.add(new TreeMap<>());
        }
        for (int i = 0; i < m; i++) {
            int a = sc.nextInt();
            int b = sc.nextInt();
            int c = sc.nextInt();
            graph.get(a).put(b, c);
            graph.get(b).put(a, c);
        }
        PriorityQueue<Path> queue = new PriorityQueue<>();
        queue.add(new Path(goal, 0));
        int[] costs = new int[n];
        Arrays.fill(costs, Integer.MAX_VALUE / 2);
        while (queue.size() > 0) {
            Path p = queue.poll();
            if (costs[p.idx] <= p.value) {
                continue;
            }
            costs[p.idx] = p.value;
            for (Map.Entry<Integer, Integer> entry : graph.get(p.idx).entrySet()) {
                queue.add(new Path(entry.getKey(), p.value + entry.getValue()));
            }
        }
        int current = start;
        int total = 0;
        ArrayList<Integer> ans = new ArrayList<>();
        ans.add(start);
        while (current != goal) {
            for (Map.Entry<Integer, Integer> entry : graph.get(current).entrySet()) {
                if (costs[entry.getKey()] + total + entry.getValue() == costs[start]) {
                    total += entry.getValue();
                    current = entry.getKey();
                    ans.add(current);
                    break;
                }
            }
        }
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < ans.size(); i++) {
            if (i > 0) {
                sb.append(" ");
            }
            sb.append(ans.get(i));
        }
        System.out.println(sb);
    }
    
    static class Path implements Comparable<Path> {
        int idx;
        int value;
        
        public Path(int idx, int value) {
            this.idx = idx;
            this.value = value;
        }
        
        public int compareTo(Path another) {
            return value - another.value;
        }
    }
}