#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <iomanip>
#include <sys/time.h>
#include <random>
using namespace std;

#define endl '\n'
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define UNIQ(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef long double ld;
typedef pair<int, string> P;
typedef pair<P, int> PP;
typedef complex<double> comp;
typedef vector< vector<ld> > matrix;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};
const int inf = 1e9 + 9;
const ll mod = 1e9 + 7;
const double eps = 1e-8;
const double pi = acos(-1);

int n, m, s, g;
int a[40000], b[40000], c[40000];

const int MAX = 220;
struct edge {
    int to, cost;
};

vector<edge> G[MAX];
int d[MAX];
string route[MAX];

string format(int k) {
    stringstream ss;
    ss << k;
    string res = ss.str();
    while (res.size() < 3) res = '0' + res;
    return res;
}

void dijkstra(int s) {
    priority_queue<PP, vector<PP>, greater<PP> > que;
    for (int i = 0; i < MAX; i++) {
        d[i] = inf;
        route[i] = "";
    }
    d[s] = 0;
    route[s] = format(s);
    que.push(PP(P(0, route[s]), s));
    while (!que.empty()) {
        PP p = que.top(); que.pop();
        int v = p.second;
        if (make_pair(d[v], route[v]) < p.first) continue;
        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (make_pair(d[e.to], route[e.to]) > make_pair(d[v] + e.cost, p.first.second+format(e.to))) {
                d[e.to] = d[v] + e.cost;
                route[e.to] = p.first.second+format(e.to);
                que.push(PP(P(d[e.to], route[e.to]), e.to));
            }
        }
    }
}

void solve() {
    for (int i = 0; i < m; i++) {
        G[a[i]].push_back(edge{b[i], c[i]});
        G[b[i]].push_back(edge{a[i], c[i]});
    }
    dijkstra(s);
    int l = route[g].size();
    for (int i = 0; i < l; i+=3) {
        cout << stoi(route[g].substr(i, 3));
        if (i+3 < l) cout << " ";
        else cout << endl;
    }
}

void input() {
    cin >> n >> m >> s >> g;
    for (int i = 0; i < m; i++) cin >> a[i] >> b[i] >> c[i];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    input();
    solve();
}