#include <bits/stdc++.h>
#define rep(i, a) for (int i = 0; i < (a); i++)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define repr(i, a) for (int i = (a) - 1; i >= 0; i--)
#define repr2(i, a, b) for (int i = (b) - 1; i >= (a); i--)
using namespace std;
typedef long long ll;
const ll inf = 1e9;
const ll mod = 1e9 + 7;

struct edge { int to, cost; };
typedef pair<int, int> P;
vector<edge> G[200];
int dp[200];

ostream &operator <<(ostream &os, const vector<int> &v) {
    rep (i, v.size()) {
        if (i) cout << " ";
        cout << v[i];
    }
    return os;
}

int main() {
    int N, M, s, t;
    cin >> N >> M >> s >> t;
    rep (i, M) {
        int a, b, c;
        cin >> a >> b >> c;
        G[a].push_back((edge){b, c});
        G[b].push_back((edge){a, c});
    }

    priority_queue<P, vector<P>, greater<P>> q;
    q.emplace(0, t);
    rep (i, N) dp[i] = inf;
    dp[t] = 0;

    while (!q.empty()) {
        P p = q.top(); q.pop();
        int v = p.second;
        
        for (edge e : G[v]) {
            if (dp[e.to] > dp[v] + e.cost) {
                dp[e.to] = dp[v] + e.cost;
                q.emplace(dp[e.to], e.to);
            }
        } 
    }

    int curr = s;
    vector<int> ans;
    ans.push_back(s);

    while (curr != t) {
        int minv = inf;
        for (edge e : G[curr]) {
            if (dp[curr] == dp[e.to] + e.cost) {
                minv = min(minv, e.to);
            }
        }
        curr = minv;
        ans.push_back(curr);
    }

    cout << ans << endl;

    return 0;
}