#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <unordered_map>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int v, w; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;

int main() {
	int N, M, S, G;
	cin >> N >> M >> S >> G;
	vector<vector<int> > adj(N, vector<int>(N)), d(N, vector<int>(N, INT_MAX / 2));
	for (int i = 0; i < N; i++)
		d[i][i] = 0;
	while (M--) {
		int a, b, c;
		cin >> a >> b >> c;
		adj[a][b] = adj[b][a] = c;
		d[a][b] = d[b][a] = c;
	}
	for (int k = 0; k < N; k++)
		for (int i = 0; i < N; i++)
			for (int j = 0; j < N; j++)
				d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
	int i = S;
	while (i != G)
		for (int j = 0; j < N; j++)
			if (adj[i][j] && adj[i][j] + d[j][G] == d[i][G]) {
				cout << i << ' ';
				i = j;
				break;
			}
	cout << G << endl;
}