#include <iostream>
#include <algorithm>
#include <queue>
#include <string>
using namespace std;

vector<int> G[210];
int cost[210][210];
int n;
const int inf=1e9;

string dijkstra(int s, int g)
{
    vector<int> d(n, inf);
    vector<unsigned int> p(n, -1u);
    priority_queue<pair<int, int>> q;
    d[g]=0;
    q.emplace(0, g);
    while (q.size()) {
        int c, v;
        tie(c, v)=q.top(); q.pop();
        if (d[v]<-c) continue;
        for(int w: G[v]) {
            if (d[w]>d[v]+cost[v][w] or d[w]==d[v]+cost[v][w] and p[w]>v) {
                d[w]=d[v]+cost[v][w];
                q.emplace(-d[w], w);
                p[w]=v;
            }
        }
    }

    string res;
    while (s!=g) {
        res+=to_string(s)+' ';
        s=p[s];
    }
    res+=to_string(g);
    return res;
}

int main()
{
    int m, s, g;
    while (cin>>n>>m>>s>>g) {
        for(int i=0;i<n;++i) G[i].clear();
        for(int i=0;i<m;++i) {
            int a, b, c; cin>>a>>b>>c;
            G[a].push_back(b);
            G[b].push_back(a);
            cost[a][b]=cost[b][a]=c;
        }
        cout<<dijkstra(s, g)<<endl;
    }
}