#include <bits/stdc++.h>

typedef long long ll;
typedef unsigned long long ull;

#define FOR(i,a,b) for(int (i)=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define RANGE(vec) (vec).begin(),(vec).end()

using namespace std;


class LexicographicOrderShortestPath {
public:
    void solve(void) {
        int N,M,S,G;
        cin>>N>>M>>S>>G;
        const int inf = 1<<30;
        vector<vector<ll>> cost(N,vector<ll>(N,0));
        vector<vector<ll>> dist(N,vector<ll>(N,inf));

        REP(i,N)
            dist[i][i] = 0;
        REP(i,M)
        {
            int a,b,c;
            cin>>a>>b>>c;
            dist[a][b] = dist[b][a] = c;
            cost[a][b] = cost[b][a] = c;
        }
        REP(k,N)
        REP(i,N)
        REP(j,N)
            dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);

        int c = S;
        cout<<c<<" ";
        while (c != G)
        {
            REP(i,N)
            {
                if (c == i)
                    continue;
                if (dist[c][G] == cost[c][i]+dist[i][G] && cost[c][i] > 0)
                {
                    c = i;
                    if (c == G)
                        cout<<c<<endl;
                    else
                        cout<<c<<" ";
                    break;
                }
            }
        }
    }
};

#if 1
int main(int argc, char *argv[])
{
        ios::sync_with_stdio(false);
        auto obj = new LexicographicOrderShortestPath();
        obj->solve();
        delete obj;
        return 0;
}
#endif