#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1 << 28;
//constexpr long long mod = 1000000007LL;
//constexpr long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;

void dijkstra(ll start, vector<vector<pair<int, ll>>>& graph, vector<ll>& dist) {
	dist[start] = 0;
	priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> pq;
	vector<bool> used(dist.size(), false);
	pq.push(make_pair(0, start));
	while (!pq.empty()) {
		ll d, node;
		tie(d, node) = pq.top();
		pq.pop();
		if (used[node]) continue;
		used[node] = true;
		for (pair<ll, ll> element : graph[node]) {
			ll new_d, new_node;
			tie(new_node, new_d) = element;
			new_d += d;
			if (new_d < dist[new_node]) {
				dist[new_node] = new_d;
				pq.push(make_pair(dist[new_node], new_node));
			}
		}
	}
}
int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/

	int n, m, st, go; scanf("%d %d %d %d", &n, &m, &st, &go);
	vector<vector<pair<int, ll>>> g(n);
	for (int i = 0; i < m; i++) {
		int a, b, c; scanf("%d %d %d", &a, &b, &c);
		g[a].emplace_back(b, c);
		g[b].emplace_back(a, c);
	}
	vector<ll> d(n, INF);
	dijkstra(go, g, d);
	queue<int> q;
	q.push(st);
	vector<int> res;
	while (!q.empty()) {
		int cur = q.front();
		q.pop();
		res.push_back(cur);
		if (cur == go) break;
		vector<pair<ll, int>> vp;
		for (auto next : g[cur]) {
			vp.emplace_back(next.second + d[next.first], next.first);
		}
		sort(vp.begin(), vp.end());
		q.push(vp[0].second);
	}
	for (int i = 0; i < res.size(); i++) {
		cout << res[i];
		if (i + 1 == res.size()) cout << "\n";
		else cout << " ";
	}
	return 0;
}