#include<bits/stdc++.h>
using namespace std;

//#define int long long

typedef long long ll;
typedef pair<int,int>pint;
typedef vector<int>vint;
typedef vector<pint>vpint;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ln <<endl
#define all(v) (v).begin(),(v).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
template<class T,class U>void chmin(T &t,U f){if(t>f)t=f;}
template<class T,class U>void chmax(T &t,U f){if(t<f)t=f;}

int N,M,X,Y;
int dist[200][200];
int G[200][200];

signed main(){
    cin>>N>>M>>X>>Y;
    fill_n(*dist,200*200,1<<25);
    rep(i,N)dist[i][i]=0;

    memset(G,-1,sizeof(G));
    rep(i,M){
        int a,b,c;
        cin>>a>>b>>c;
        G[a][b]=G[b][a]=c;
        dist[a][b]=dist[b][a]=c;
    }
    rep(k,N)rep(i,N)rep(j,N)chmin(dist[i][j],dist[i][k]+dist[k][j]);

    int v=X;
    vint ans;ans.pb(X);

    while(v!=Y){
        int u=114514;
        rep(i,N){
            if(dist[Y][i]+G[v][i]==dist[Y][v])chmin(u,i);
        }
        ans.pb(u);
        v=u;
    }

    rep(i,ans.size()){
        if(i)cout<<" ";
        cout<<ans[i];
    }cout<<endl;
    return 0;
}