#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)--)
#define debug(x) cerr << #x << ": " << x << endl
const int INF = 1e9;                          const LL LINF = 1e16;
const LL MOD = 1000000007;                    const double PI = acos(-1.0);
int DX[8] = { 0, 0, 1, -1, 1, 1, -1, -1 };    int DY[8] = { 1, -1, 0, 0, 1, -1, 1, -1 };

/* -----  2018/05/05  Problem: yukicoder 160  / Link: http://yukicoder.me/problems/no/160  ----- */
/* ------問題------



-----問題ここまで----- */
/* -----解説等-----



----解説ここまで---- */

VI Dijkstra(vector<vector<PLL>>& G, int s, int t) {
	swap(s, t);
	VL dist(SZ(G), LINF);
	dist[s] = 0;
	priority_queue<PLL, vector<PLL>, greater<PLL>> que;
	que.push(PLL(0LL, s));

	while (!que.empty()) {
		PLL p = que.top(); que.pop();
		int v; long long 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;
				que.push(PLL(dist[nv], nv));
			}
		}
	}
	int cur = t;
	VI path{ t };
	while (cur != s) {
		int nx_v = INF;
		FOR(i, 0, (int)G[cur].size()) {
			if (dist[cur] == dist[G[cur][i].first] + G[cur][i].second) {
				nx_v = min(nx_v, (int)G[cur][i].first);
			}
		}
		cur = nx_v; path.push_back(cur);
	}
	return path;
}


LL ans = 0LL;

int main() {
	cin.tie(0);
	ios_base::sync_with_stdio(false);

	int N, M, S, T;
	cin >> N >> M >> S >> T;
	vector<vector<PLL>> 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 = Dijkstra(G, S, T);
	FOR(i, 0, SZ(path)) {
		cout << path[i] << " \n"[i == SZ(path) - 1];
	}
	return 0;
}