#include <bits/stdc++.h>
using namespace std;

using VS = vector<string>;    using LL = long long;
using VI = vector<int>;       using VVI = vector<VI>;
using PII = pair<int, int>;   using PLL = pair<LL, LL>;
using VL = vector<LL>;        using VVL = vector<VL>;

#define ALL(a)  begin((a)),end((a))
#define RALL(a) (a).rbegin(), (a).rend()
#define SZ(a) int((a).size())
#define SORT(c) sort(ALL((c)))
#define RSORT(c) sort(RALL((c)))
#define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))
#define FOR(i, s, e) for (int(i) = (s); (i) < (e); (i)++)
#define FORR(i, s, e) for (int(i) = (s); (i) > (e); (i)--)
//#pragma GCC optimize ("-O3") 
#ifdef YANG33
#include "mydebug.hpp"
#else
#define DD(x) 
#endif
const int INF = 1e9;                          const LL LINF = 1e16;
const LL MOD = 1000000007;                    const double PI = acos(-1.0);


// Etp(Vtp,+), Vtp(>,==)
template<typename Etp, typename Vtp>
VI DijkstraPath(vector<vector<pair<int, Etp>>>& G, int s, int t,
	Vtp init, Vtp inf,
	bool dictmin = 0) {
	if (dictmin)swap(s, t);
	vector<Vtp> dist(SZ(G), inf);
	VI rev(SZ(G), -1);
	priority_queue<pair<Vtp, int>, vector<pair<Vtp, int>>, greater<pair<Vtp, int>>> que;
	dist[s] = init;
	que.push(pair<Vtp, int>(init, s));

	while (!que.empty()) {
		PLL p = que.top(); que.pop();
		int v; Vtp d; tie(d, v) = p;
		if (d > dist[v]) continue;
		FOR(i, 0, (int)G[v].size()) {
			int nv = G[v][i].first;
			if (dist[nv] > dist[v] + G[v][i].second) {
				dist[nv] = dist[v] + G[v][i].second;
				rev[nv] = v;
				DD(de(nv, v));
				que.push(pair<Vtp,int>(dist[nv], nv));
			}
			else if (dictmin && dist[nv] == dist[v] + G[v][i].second) {
				if (rev[nv] > v) {
					rev[nv] = v;
				}
			}
		}
	}
	int cur = t;
	VI path{ t };
	while (cur != s) {
		cur = rev[cur]; path.push_back(cur);
	}

	return path;
}


void solve_yukicoder_160() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);

	int N, M, S, T;
	cin >> N >> M >> S >> T;
	vector<vector<PII>> G(N);
	FOR(i, 0, M) {
		int a, b, c; cin >> a >> b >> c;
		G[a].push_back(PII(b, c));
		G[b].push_back(PII(a, c));
	}
	VI path = DijkstraPath<int, int>(G, S, T, 0, INF, 1);
	FOR(i, 0, SZ(path)) {
		cout << path[i] << " \n"[i == SZ(path) - 1];
	}

}


int main() {
	 solve_yukicoder_160();


	return 0;
}