#include<bits/stdc++.h>
using namespace std;
#include<atcoder/all>
using namespace atcoder;
using ll = long long;
int n,m,s,g;
using P = pair<int,int>;
vector<vector<P>> G;

void solve(){
	vector<vector<int>> dist(n,vector<int>(n,INT_MAX/2));
	for(int i =0;i<n;i++)dist[i][i] = 0;
	for(int i = 0;i<n;i++){
		for(auto &[to,cost]:G[i]){
			dist[i][to] = cost;
			dist[to][i] = cost;
		}
	}
	for(int k = 0;k<n;k++){
		for(int i = 0;i<n;i++){
			for(int j = 0;j<n;j++){
				dist[i][j] = min(dist[i][j],dist[i][k]+dist[k][j]);
			}
		}
	}
	int sumcost = dist[s][g];
	cout<<s<<' ';
	int cur = s;
	auto dist2 = vector<vector<int>>(n,vector<int>(n,INT_MAX/2));
	for(int i = 0;i<n;i++){
		for(auto &[to,cost]:G[i]){
			dist2[i][to] = cost;
			dist2[to][i] = cost;
		}
	}
	while(cur!=g){
		for(int i = 0;i<n;i++){
			if(dist2[cur][i]+dist[i][g]==sumcost){
				sumcost -= dist2[cur][i];
				cout<<i<<' ';
				cur = i;
				break;
			}
		}
	}
	//cout<<g;
	cout<<endl;
}

signed main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cin >> n >> m >> s >> g;
	G = vector<vector<P>>(n);
	for(int i = 0;i<m;i++){
		int a,b,c;
		cin >> a >> b >> c;
		G[a].push_back(P(b,c));
	}
	solve();
}