#include <bits/stdc++.h>
using namespace std;
#define REP(i, n)           for(int(i)=0;(i)<(n);++(i))

int g[222][222],r[222][222];

int main(){
    do { cin.tie(0); ios_base::sync_with_stdio(false); } while(0);

    int N,M,S,G;
    cin >> N >> M >> S >> G;

    const int INF = 1<<28;
    REP(i,N)REP(j,N) g[i][j] = INF;
    REP(i,M){
        int a,b,c;
        cin >> a >> b >> c;
        g[a][b] = g[b][a] = c;
        r[a][b] = r[b][a] = c;
    }
    REP(i,N) g[i][i] = 0;

    REP(k,N)REP(i,N)REP(j,N)
        g[i][j] = min(g[i][j], g[i][k] + g[k][j]);

    int v = S;
    cout << S;
    while(v != G){
        REP(i,N) if(v != i && r[v][i] == g[v][i] && g[v][G] == g[v][i]+g[i][G]){ v = i; break; }
        cout << " " << v;
    }
    cout << endl;

    return 0;
}