#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
using namespace std;

template <class T>
class EdgeBase
{
public:
    int to;
    T cost;
    EdgeBase(){};
    EdgeBase(int to0, T cost0){to = to0; cost = cost0;}
};
typedef EdgeBase<int> Edge;

template<class T>
void shortestPath(const vector<vector<EdgeBase<T> > >& edges, int start, vector<T>& dist)
{
    const T INF = numeric_limits<T>::max();
    const T EPS = static_cast<T>(1.0e-10);

    dist.assign(edges.size(), INF);
    dist[start] = 0;
    priority_queue<pair<T,int>, vector<pair<T,int> >, greater<pair<T,int> > > q;
    q.push(make_pair(0, start));

    while(!q.empty()){
        pair<T, int> p = q.top();
        q.pop();
        int v = p.second;
        if(dist[v] < p.first - EPS)
            continue;
        for(unsigned i=0; i<edges[v].size(); ++i){
            EdgeBase<T> e = edges[v][i];
            if(dist[v] + e.cost < dist[e.to] - EPS){
                dist[e.to] = dist[v] + e.cost;
                q.push(make_pair(dist[e.to], e.to));
            }
        }
    }
}

int main()
{
    int n, m, s, g;
    cin >> n >> m >> s >> g;

    vector<vector<Edge> > edges(n);
    for(int i=0; i<m; ++i){
        int a, b, c;
        cin >> a >> b >> c;
        edges[a].push_back(Edge(b, c));
        edges[b].push_back(Edge(a, c));
    }
    vector<int> dist;
    shortestPath(edges, s, dist);

    queue<int> q;
    vector<int> to(n, INT_MAX);
    q.push(g);
    to[g] = -1;
    while(!q.empty()){
        int x = q.front();
        q.pop();
        for(unsigned i=0; i<edges[x].size(); ++i){
            int y = edges[x][i].to;
            if(dist[y] + edges[x][i].cost == dist[x]){
                if(to[y] == INT_MAX)
                    q.push(y);
                to[y] = min(to[y], x);
            }
        }
    }

    cout << s;
    int x = s;
    while(to[x] != -1){
        x = to[x];
        cout << ' ' << x;
    }
    cout << endl;

    return 0;
}