#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <complex>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <bitset>
#include <ctime>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <cassert>
#include <cstddef>
#include <iomanip>
#include <numeric>
#include <tuple>
#include <sstream>
#include <fstream>
#include <random>

#define REP(i, n) for (int (i) = 0; (i) < (n); (i)++)
#define FOR(i, a, b) for (int (i) = (a); (i) < (b); (i)++)
#define RREP(i, a) for (int (i) = (a) - 1; (i) >= 0; (i)--)
#define FORR(i, a, b) for (int (i) = (a) - 1; (i) >= (b); (i)--)
#define PI acos(-1.0)
#define DEBUG(C) cerr << C << endl;
#define VI vector <int>
#define VII vector <VI>
#define VL vector <LL>
#define VLL vector <VL>
#define VD vector <double>
#define VDD vector <VD>
#define PII pair <int, int>
#define PDD pair <double, double>
#define PLL pair <LL, LL>
#define VPII vector <PII>
#define ALL(a) (a).begin(), (a).end()
#define SORT(a) sort(ALL(a))
#define REVERSE(a) reverse(ALL(a))
#define MP make_pair
#define EB emplace_back
#define FORE(a, b) for (auto &&a : b)
#define FIND(s, n) (s.find(n) != s.end())

using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
const int INF = 1e9;
const int MOD = INF + 7;
const LL LLINF = 1e18;

int N, M, S, G;
vector<VPII> graph;
VI mincost;

int main(void) {
    cin >> N >> M >> S >> G;
	graph.resize(N);
	mincost.resize(N, INF);
	REP(i, M) {
		int a, b, c;
		cin >> a >> b >> c;
		graph[a].EB(MP(b, c));
		graph[b].EB(MP(a, c));
	}
	//<cost, now>
	priority_queue<PII> pq;
	pq.push(MP(0, G));
	while (!pq.empty()) {
		int cost, now;
		tie(cost, now) = pq.top(); pq.pop();
        cost *= -1;
		if (cost < mincost[now]) mincost[now] = cost;
        else continue;
		FORE(el, graph[now]) {
			int next, ncost;
			tie(next, ncost) = el;
			if (mincost[next] != INF) continue;
			pq.push(MP(-(cost + ncost), next));
		}
	}
	//cout << mincost[S] << endl;
	//<now, cost>
	queue<PII> q;
	REP(i, N) SORT(graph[i]);
	q.push(MP(S, mincost[S]));
	VI ans; ans.EB(S);
	while (!q.empty()) {
		int now, cost;
		tie(now, cost) = q.front(); q.pop();
		if (now == G) break;
		FORE(el, graph[now]) {
			int nc, next;
			tie(next, nc) = el;
			if (cost - nc != mincost[next]) continue;
			ans.EB(next);
			q.push(MP(next, mincost[next]));
            break;
		}
	}
	REP(i, ans.size()) {
		cout << (i == 0 ? "" : " ") << ans[i];
	}
	cout << endl;
	return 0;
}