use std::io;
use std::cmp;
use std::cmp::Ordering;
use std::usize;
use std::collections::BinaryHeap;

fn main() {
    solve();
}

fn solve() {
    let mut str = String::new();
    io::stdin().read_line(&mut str).unwrap();
    let mut input: Vec<usize> = str.split_whitespace().map(|x| x.parse().unwrap()).collect();
    let n = input[0];
    let m = input[1];
    let s = input[2];
    let g = input[3];

    let mut graph: Vec<Vec<Edge>> = (0..n).map(|_| Vec::new()).collect();

    for _ in 0..m {
        str = String::new();
        io::stdin().read_line(&mut str).unwrap();
        input = str.split_whitespace().map(|x| x.parse().unwrap()).collect();
        graph[input[0]].push(Edge { to: input[1], cost: input[2] });
        graph[input[1]].push(Edge { to: input[0], cost: input[2] });
    }

    let mut dist: Vec<_> = (0..n).map(|_| usize::MAX).collect();
    let mut pre: Vec<_> = (0..n).map(|i| i).collect();
    let mut heap = BinaryHeap::new();

    heap.push(Node { id: g, cost: 0 });
    dist[g] = 0;

    while let Some(Node {id, cost}) = heap.pop() {
        if dist[id] < cost {
            continue;
        }

        for edge in &graph[id] {
            if cost + edge.cost < dist[edge.to] {
                heap.push(Node { id: edge.to, cost: cost + edge.cost });
                dist[edge.to] = cost + edge.cost;
                pre[edge.to] = id;
            }

            if cost + edge.cost == dist[edge.to] {
                pre[edge.to] = cmp::min(pre[edge.to], id);
            }
        }
    }

    let mut current = s;

    while current != g {
        print!("{} ", current);
        current = pre[current];
    }

    println!("{}", current);
}

struct Edge {
    to: usize,
    cost: usize,
}

#[derive(Copy, Clone, Eq, PartialEq)]
struct Node {
    id: usize,
    cost: usize,
}

impl Ord for Node {
    fn cmp(&self, other: &Self) -> Ordering {
        other.cost.cmp(&self.cost).then_with(|| self.id.cmp(&other.id))
    }
}

impl PartialOrd for Node {
    fn partial_cmp(&self, other: &Node) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}