#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>

#include <iostream>
#include <complex>
#include <string>
#include <algorithm>
#include <numeric>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>

#include <functional>
#include <cassert>

typedef long long ll;
using namespace std;

#ifndef LOCAL
#define debug(x) ;
#else
#define debug(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl;

template <typename T1, typename T2>
ostream &operator<<(ostream &out, const pair<T1, T2> &p) {
  out << "{" << p.first << ", " << p.second << "}";
  return out;
}

template <typename T>
ostream &operator<<(ostream &out, const vector<T> &v) {
  out << '{';
  for (const T &item : v) out << item << ", ";
  out << "\b\b}";
  return out;
}
#endif

#define mod 1000000007 //1e9+7(prime number)
#define INF 1000000000 //1e9
#define LLINF 2000000000000000000LL //2e18
#define SIZE 210

ll dist[SIZE][SIZE];
ll dist_input[SIZE][SIZE];

int main(){
  int N, M, S, G;

  scanf("%d%d%d%d", &N, &M, &S, &G);

  for(int i=0;i<N;i++) {
    for(int j=0;j<N;j++) {
      dist[i][j] = LLINF;
      dist_input[i][j] = LLINF;
    }
    dist[i][i] = 0;
  }

  for(int i=0;i<M;i++){
    int a, b, c;
    scanf("%d%d%d", &a, &b, &c);
    dist[a][b] = c;
    dist[b][a] = c;
    dist_input[a][b] = c;
    dist_input[b][a] = c;
  }

  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]);
      }
    }
  }

  vector<int> ans;
  ans.push_back(S);
  int now = S;

  while(now != G){
    for(int i=0;i<N;i++){
      if (i != now && dist_input[now][i] + dist[i][G] == dist[now][G]) {
        ans.push_back(i);
        now = i;
        break;
      }
    }
  }

  for(int i=0;i<ans.size();i++){
    printf("%d%c", ans[i], " \n"[i+1 == ans.size()]);
  }

  return 0;
}