#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())
#define endl "\n"

template<class T>
struct Dijkstra {
    const T inf = numeric_limits<T>::max() / 2 - 1;
    vector<T> dist;
    vector<int> path;
    
    Dijkstra() {}
    Dijkstra(int n) {
        graph.resize(n);
        dist.resize(n);
        prev.resize(n);
    }
    
    void add_edge(int from, int to, T cost) {
        graph[from].emplace_back(to, cost);
    }
    
    void get_distance(int from) {
        priority_queue<pair<T, int>, vector<pair<T, int>>, greater<pair<T, int>>> pq;
        fill(dist.begin(), dist.end(), inf);
        fill(prev.begin(), prev.end(), -1);
        dist[from] = 0;
        pq.push(make_pair(0, from));
        while(!pq.empty()) {
            pair<T, int> p = pq.top(); pq.pop();
            if (dist[p.second] < p.first) continue;
            for (auto e : graph[p.second]) {
                if (
                    (dist[e.first] > (dist[p.second] + e.second)) ||
                    ((dist[e.first] == (dist[p.second] + e.second)) && (prev[e.first] > p.second))
                ) {
                    dist[e.first] = dist[p.second] + e.second;
                    prev[e.first] = p.second;
                    pq.push(make_pair(dist[e.first], e.first));
                }
            }
        }
    }
    
    void get_path(int to) {
        path = vector<int>(0);
        for (; to != -1; to = prev[to]) {
            path.push_back(to);
        }
        reverse(path.begin(), path.end());
    }
    
private:
    vector<vector<pair<int, T>>> graph;
    vector<T> prev;
};

struct S {
    ll a, b, c;
    
    bool operator<(const S &sb) const {
        if (a == sb.a) return b < sb.b;
        return a < sb.a;
    }
};

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    ll n, m, s, g;
    cin >> n >> m >> s >> g;
    Dijkstra<ll> di(n);
    vector<S> vs(2 * m);
    rep(i, m) {
        cin >> vs[i * 2].a >> vs[i * 2].b >> vs[i * 2].c;
        vs[i * 2 + 1].a = vs[i * 2].b;
        vs[i * 2 + 1].b = vs[i * 2].a;
        vs[i * 2 + 1].c = vs[i * 2].c;
    }
    sort(all(vs));
    rep(i, 2 * m) di.add_edge(vs[i].a, vs[i].b, vs[i].c);
    di.get_distance(s);
    di.get_path(g);
    ll pl = sz(di.path);
    rep(i, pl) printf("%lld%s", di.path[i], (i == (pl - 1)) ? "\n" : " ");
    return 0;
}