#include <bits/stdc++.h>

using namespace std;

#define rep(i, n) for(int i = 0; i < (int)n; ++i)
#define FOR(i, a, b) for(int i = a; i < (int)b; ++i)
#define rrep(i, n) for(int i = ((int)n - 1); i >= 0; --i)

typedef long long ll;
typedef long double ld;

const int Inf = 1e9;
const double EPS = 1e-9;
const int MOD = 1e9 + 7;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(0);
    int n, m, s, g;
    cin >> n >> m >> s >> g;
    vector<vector<int> > d(n, vector<int>(n, Inf));
    vector<vector<int> > next(n, vector<int>(n));
    rep (i, n) {
        rep (j, n) next[i][j] = j;
        d[i][i] = 0;
    }
    rep (i, m) {
        int a, b, c;
        cin >> a >> b >> c;
        d[a][b] = d[b][a] = c;
    }
    rep (k, n) {
        rep (i, n) {
            rep (j, n) {
                if (d[i][j] > d[i][k] + d[k][j]) {
                    d[i][j] = d[i][k] + d[k][j];
                    next[i][j] = next[i][k];
                } else if (k != i && d[i][k] + d[k][j] == d[i][j]) {
                    next[i][j] = min(next[i][j], next[i][k]);
                }
            }
        }
    }
    for (int x = s; x != g; x = next[x][g]) {
        cout << x << " ";
    }
    cout << g << endl;
    
    return 0;
}