// Enjoy your stay.

#include <bits/stdc++.h>

#define long long long
#define LOOPVAR_TYPE long

#define all(x) (x).begin(), (x).end()
#define sz(x) ((LOOPVAR_TYPE)(x).size())
#define foreach(it, X) for(__typeof((X).begin()) it = (X).begin(); it != (X).end(); it++)
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define _rep(i, n) _rep2(i, 0, n)
#define _rep2(i, a, b) for(LOOPVAR_TYPE i = (LOOPVAR_TYPE)(a); i < (LOOPVAR_TYPE)(b); i++)
#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)

#define fir first
#define sec second
#define mp make_pair
#define mt make_tuple
#define pb push_back

const double EPS = 1e-9;
const double PI = acos(-1.0);
const long INF = 1070000000LL;
const long MOD = 1000000007LL;

using namespace std;

typedef istringstream iss;
typedef stringstream sst;
typedef pair<LOOPVAR_TYPE, LOOPVAR_TYPE> pi;
typedef vector<LOOPVAR_TYPE> vi;

int N,M,S,G;
int d[222][222];
int d2[222][222];


int main(){
	cin.tie(0);
	ios_base::sync_with_stdio(0);
	
	cin>>N>>M>>S>>G;
	rep(i,N)rep(j,N){
		d[i][j] = i==j ? 0 : INF;
		d2[i][j] = i==j ? 0 : INF;
	}
	rep(i,M){
		int a,b,c;
		cin>>a>>b>>c;
		d[a][b] = d[b][a] = c;
		d2[a][b] = d2[b][a] = c;
	}
	rep(k,N)rep(i,N)rep(j,N)d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
	int cur = S;
	cout<<S;
	while(cur != G){
		int nx = -1;
		rep(i,N)if(i != cur && d2[cur][i] + d[i][G] == d[cur][G]){
			nx = i; break;
		}
		cout<<" "<<nx;
		cur = nx;
	}
	cout<<endl;
}