#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ALL(v) v.begin(), v.end()
typedef long long ll;

#include <bits/stdc++.h>
using namespace std;

const ll INF=1LL<<60;

struct Edge{
  int to;
  ll w;
  Edge(int to,ll w) : to(to),w(w) {}
};

using Graph=vector<vector<Edge>>;
using pli=pair<ll,int>;

template<class T> bool chmin(T& a,T b){
  if(a>b){
    a=b;
    return true;
  }
  return false;
}

Graph G;
vector<ll> dijkstra(int s){
  int n=G.size();
  vector<ll> dist(n,INF);
  dist[s]=0;
  
  priority_queue<pli,vector<pli>,greater<pli>> que;
  que.push({dist[s],s});
  
  while(!que.empty()){
    int v=que.top().second;
    ll d=que.top().first;
    que.pop();
    
    if(d>dist[v]) continue;

    for(auto e:G[v]){
      if(chmin(dist[e.to],dist[v]+e.w)){
        que.push({dist[e.to],e.to});
      }
    }
  }
  return dist;
}

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

  int n,m,p,s,g;
  cin>>n>>m>>p>>s>>g;
  s--,g--;
  
  G.resize(2*n);
  rep(i,m){
    int u,v;
    cin>>u>>v;
    u--,v--;
    G[u].push_back(Edge(v+n,1));
    G[v+n].push_back(Edge(u,1));
    G[u+n].push_back(Edge(v,1));
    G[v].push_back(Edge(u+n,1));
  }
  
  vector<ll> dis=dijkstra(s);
  vector<ll> dis1=dijkstra(g);
  
  vector<ll> ANS;
  if(p%2==0){
    rep(i,n){
      if(dis[i]+dis1[i]<=p || dis[i+n]+dis1[i+n]<=p) ANS.push_back(i+1);
    }
  }
  else{
    rep(i,n){
      if(dis[i]+dis1[i+n]<=p || dis[i+n]+dis1[i]<=p) ANS.push_back(i+1);
    }
  }
  
  int a=ANS.size();
  if(a==0) cout<<-1<<endl;
  else{
    cout<<a<<endl;
    rep(i,a) cout<<ANS[i]<<endl;
  }
  
  return 0;
}