#include <bits/stdc++.h>

using namespace std;

template<typename T> class Ordered {
public:
  template<typename V> bool operator==(const V& v) const {
    return !(static_cast<T>(v) < static_cast<const T&>(*this) || static_cast<const T&>(*this) < static_cast<T>(v));
  }
  
  template<typename V> bool operator!=(const V& v) const {
    return static_cast<T>(v) < static_cast<const T&>(*this) || static_cast<const T&>(*this) < static_cast<T>(v);
  }

  template<typename V> bool operator>(const V& v) const {
    return static_cast<T>(v) < static_cast<const T&>(*this);
  }

  template<typename V> bool operator<=(const V& v) const {
    return !(static_cast<T>(v) < static_cast<const T&>(*this));
  }

  template<typename V> bool operator>=(const V& v) const {
    return !(static_cast<const T&>(*this) < static_cast<T>(v));
  }
};

template<typename Edge> class Graph {
public:
  typedef Edge EdgeType;
  virtual int size() const = 0;
  template<typename... Args> void addEdge(Args...) {}
  template<typename... Args> void addUndirectedEdge(Args...) {}
  virtual vector<Edge> getEdges() const = 0;
  virtual vector<Edge> getEdges(int from) const = 0;
  virtual vector<Edge> getEdges(int from, int to) const = 0;
  virtual int getDegree(int v) const = 0;
};

template<typename Edge> class AdjacencyList : public Graph<Edge> {
protected:
  vector<vector<Edge>> graph;

public:
  AdjacencyList(int n) : graph(n) {}

  int size() const {
    return graph.size();
  }
  
  template<typename... Args> void addEdge(Args... args) {
    Edge edge(args...);
    graph[edge.from].emplace_back(edge);
  }

  template<typename... Args> void addUndirectedEdge(Args... args) {
    Edge edge(args...);
    addEdge(edge);
    swap(edge.from, edge.to);
    addEdge(edge);
  }

  vector<Edge> getEdges() const {
    vector<Edge> res;
    for (const auto& edges : graph) {
      res.insert(res.end(), edges.begin(), edges.end());
    }
    return res;
  }

  vector<Edge> getEdges(int from) const {
    return graph[from];
  }

  vector<Edge> getEdges(int from, int to) const {
    vector<Edge> res;
    for (const auto& edge : graph[from]) {
      if (edge.to == to) res.emplace_back(edge);
    }
    return res;
  }

  int getDegree(int v) const {
    return graph[v].size();
  }

  vector<Edge>& operator[](int v) {
    return graph[v];
  }
};

template<typename Graph, typename State> class Search {
protected:
  typedef typename Graph::EdgeType Edge;

  const Graph graph;
  vector<bool> visited;

  virtual void push(const State&) = 0;
  virtual State next() = 0;
  virtual bool isRunning() = 0;

  virtual void visit(const State&) {}
  virtual bool canPruning(const State&) {return false;}

public:
  Search(const Graph& graph) : graph(graph), visited(graph.size(), false) {}

  void solve(int from) {
    push(State(from));
    while (isRunning()) {
      State now = next();
      int pos = now.getPos();
      if (visited[pos]) continue;
      visited[pos] = true;
      visit(now);
      for (const Edge& edge : graph.getEdges(pos)) {
        State nextState = now.next(edge);
        if (visited[nextState.getPos()]) continue;
        if (canPruning(nextState)) continue;
        push(nextState);
      }
    }
  }

  bool isReachable(int v) {
    return visited[v];
  }
};

template<typename Edge> class Tree {
public:
  vector<Edge> parent;
  vector<vector<int>> children;
  vector<int> depth;

  Tree() {}

  Tree(int n) : children(n), depth(n, -1) {
    for (int i = 0; i < n; ++i) parent.emplace_back(i, i);
  }

  int size() const {
    return parent.size();
  }
  
  template<typename... Args> void addEdge(Args... args) {
    Edge edge(args...);
    parent[edge.from] = edge;
    if (edge.from != edge.to) children[edge.to].emplace_back(edge.from);
  }

  int getDepth(int v) {
    if (depth[v] != -1) return depth[v];
    if (parent[v].to == v) return depth[v] = 0;
    return depth[v] = getDepth(parent[v].to) + 1;
  }

  vector<int> getPath(int v) {
    vector<int> res{v};
    while (v != parent[v].to) {
      v = parent[v].to;
      res.emplace_back(v);
    }
    return res;
  }
};

template<typename Edge> struct DijkstraState {
  typedef typename Edge::CostType Cost;

  Edge edge;
  Cost cost;

  DijkstraState(int pos) : edge(pos, pos), cost(0) {}

  DijkstraState(const Edge& edge, Cost cost) : edge(edge), cost(cost) {}

  DijkstraState next(const Edge& edge) const {
    return DijkstraState(edge, cost + edge.cost);
  }

  bool operator<(const DijkstraState& state) const {
    return cost > state.cost;
  }

  int getPos() const {
    return edge.to;
  }
};

template<typename Graph, bool Restoration = false, typename State = DijkstraState<typename Graph::EdgeType>> class Dijkstra : public Search<Graph, State> {
protected:
  typedef typename Graph::EdgeType Edge;
  typedef typename Edge::CostType Cost;

  const Cost INF = numeric_limits<Cost>::max();

  priority_queue<State> que;

  void push(const State& state) {
    que.push(state);
    dis[state.getPos()] = state.cost;
  }

  State next() {
    State now = que.top();
    que.pop();
    return now;
  }

  bool isRunning() {
    return !que.empty();
  }

  void visit(const State& state) {
    if (Restoration) {
      auto e = state.edge;
      swap(e.from, e.to);
      shortestPathTree.addEdge(e);
    }
  }

  bool canPruning(const State& state) {
    return dis[state.getPos()] <= state.cost;
  }

public:
  vector<Cost> dis;
  Tree<Edge> shortestPathTree;

  Dijkstra(const Graph& graph) : Search<Graph, State>(graph), dis(graph.size(), INF) {
    if (Restoration) shortestPathTree = Tree<Edge>(graph.size());
  }
};

template<typename Graph> inline Dijkstra<Graph> shortestPath(Graph& graph, int from) {
  Dijkstra<Graph> dijkstra(graph);
  dijkstra.solve(from);
  return dijkstra;
}

template<typename Graph> inline typename Graph::EdgeType::CostType shortestPath(Graph& graph, int from, int to) {
  Dijkstra<Graph> dijkstra(graph);
  dijkstra.solve(from);
  return dijkstra.dis[to];
}

template<typename Graph> inline Dijkstra<Graph, true> shortestPathTree(Graph& graph, int from) {
  Dijkstra<Graph, true> dijkstra(graph);
  dijkstra.solve(from);
  return dijkstra;
}

template<typename T> string to_string(const T& v) {
  string str;
  for (const auto& i : const_cast<T&>(v)) str += to_string(i) + " ";
  return str.substr(0, max(0, (int)str.size() - 1));
}

struct Cost : public Ordered<Cost> {
  int dist, from;

  constexpr Cost() : dist(0), from(-1) {}

  constexpr Cost(int dist) : dist(dist), from(-1) {}

  constexpr Cost(int dist, int to) : dist(dist), from(to) {}

  Cost operator+(const Cost& cost) const {
    return Cost(dist + cost.dist, cost.from);
  }

  bool operator<(const Cost& cost) const {
    if (dist != cost.dist) return dist < cost.dist;
    return from < cost.from;
  }
};

namespace std {
  template<> constexpr Cost numeric_limits<Cost>::max() {
    return Cost(numeric_limits<int>::max(), numeric_limits<int>::max());
  }
}

struct Edge {
  typedef Cost CostType;
  int from, to;
  Cost cost;
  Edge(int from, int to) : from(from), to(to), cost(0, from) {};
  Edge(int from, int to, int cost) : from(from), to(to), cost(cost, from) {};
};

int main() {
  int n, m, s, g;
  cin >> n >> m >> s >> g;
  AdjacencyList<Edge> graph(n);
  for (int i = 0; i < m; ++i) {
    int a, b, c;
    cin >> a >> b >> c;
    graph.addEdge(a, b, c);
    graph.addEdge(b, a, c);
  }
  cout << to_string(shortestPathTree(graph, g).shortestPathTree.getPath(s)) << endl;
}