#include <algorithm>
#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
using namespace std;

template<typename T>
struct Edge { int src, dst; T cost;
    Edge(int dst, T cost) : src(-1), dst(dst), cost(cost) { }
    Edge(int src, int dst, T cost) : src(src), dst(dst), cost(cost) { }
};
template<typename T> using Edges = vector<Edge<T>>;
template<typename T> using WeightedGraph = vector<Edges<T>>;
template<typename T> using Matrix = vector<vector<T>>;

template<typename T>
Matrix<T> warshall_floyd(Matrix<T> &g) {
    Matrix<T> d(g);
    const T INF = numeric_limits<T>::max();
    for (int k = 0; k < d.size(); k++) {
        for (int i = 0; i < d.size(); i++) if (d[i][k] != INF) {
            for (int j = 0; j < d.size(); j++) if (d[k][j] != INF) {
                d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
            }
        }
    }
    return d;
}
template<typename T>
vector<int> build_path(Matrix<T> &mat, Matrix<T> &dist, int s, int t) {
    vector<int> path{s};
    while (s != t) {
        for (int k = 0; k < mat.size(); k++) if (s != k) {
            if (mat[s][k] + dist[k][t] == dist[s][t]) {
                path.emplace_back(k); s = k; break;
            }
        }
    }
    return path;
}

int main() {
    const int INF = numeric_limits<int>::max();
    int N, M, S, G; cin >> N >> M >> S >> G;
    Matrix<int> mat(N, vector<int>(N, INF));
    for (int i = 0; i < N; i++) mat[i][i] = 0;
    while (M--) {
        int a, b, c; cin >> a >> b >> c;
        mat[a][b] = mat[b][a] = c;
    }
    Matrix<int> dist = warshall_floyd(mat);
    for (int v: build_path(mat, dist, S, G)) cout << v << " \n"[v == G];
    return 0;
}