#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>

using namespace std;

template<typename T> using pq = priority_queue<T, vector<T>, greater<T>>;
 
int main(){
 
    long long N, M, A, B, C, S, G;
    long long from, alt, d;
    cin >> N >> M >> S >> G;
    pq<pair<long long, long long>> que;
    vector<vector<pair<long long, long long>>> E(N);
    vector<long long> dist(N, 1e18), ans;
    vector<bool> visit(N);
 
    for (int i=0; i < M; i++){
        cin >> A >> B >> C;
        E[A].push_back({B, C});
        E[B].push_back({A, C});
    }
    for (auto &x : E) sort(x.begin(), x.end());
 
    dist[G] = 0;
    que.push({0, G});
 
    while(!que.empty()){
        tie(d, from) = que.top();
        que.pop();
        if (visit[from]) continue;
        visit[from] = 1;
        for (auto [to, C] : E[from]){
            alt = d + C;
            if (alt < dist[to]){
                dist[to] = alt;
                que.push({dist[to], to});
            }
        }
    }

    ans.push_back(S);
    long long now = S;

    while(now != G){
        for (auto [x, y] : E[now]){
            if (dist[x] == dist[now] - y){
                now = x;
                ans.push_back(now);
            }
        }
    }

    for (auto x : ans) cout << x << " ";
    cout << endl;
 
    return 0;
}