#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

using ll = long long;
constexpr int INF = 1001001001;
// constexpr int mod = 1000000007;
constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, M, S, G;
    cin >> N >> M >> S >> G;
    using edge = pair<int, int>;
    vector<vector<edge>> g(N);
    for(int i = 0; i < M; ++i){
        int a, b, c;
        cin >> a >> b >> c;
        g[a].emplace_back(b, c);
        g[b].emplace_back(a, c);
    }

    auto dijkstra = [&](int s){
        vector<int> dist(N, INF);
        priority_queue<edge, vector<edge>, greater<edge>> que;
        dist[s] = 0;
        que.emplace(0, s);
        while(!que.empty()){
            auto [d, from] = que.top();
            que.pop();
            if(d > dist[from])  continue;
            for(auto [to, cost] : g[from]){
                if(chmin(dist[to], dist[from] + cost)){
                    que.emplace(dist[to], to);
                }
            }
        }
        return dist;
    };

    auto distS = dijkstra(S);
    auto distG = dijkstra(G);
    vector<int> ord(1, S);
    vector<bool> used(N);
    used[S] = true;
    while(S != G){
        int nv = N;
        for(auto [v, cost] : g[S]){
            if(used[v]) continue;
            if(distS[S] + cost + distG[v] == distS[G]){
                chmin(nv, v);
            }
        }
        S = nv;
        ord.emplace_back(S);
        used[S] = true;
    }

    int V = ord.size();
    for(int i = 0; i < V; ++i){
        cout << ord[i] << (i == V - 1 ? '\n' : ' ');
    }

    return 0;
}