#if loc||local
#define _GLIBCXX_DEBUG
#endif

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

#define rep(i,n) for(ll i=0;i<(n);++i)
using ll = int_fast64_t;
using pll = pair<ll,ll>;
constexpr ll INF = 1LL<<60;
constexpr ll MOD = 1e9+7;
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}return 0;}
#if loc||local
template<class T>void dump(T&& t){cerr<<t<<endl;}
template<class T,class... Ts> void dump(T&& h, Ts&&... t){cerr<<h<<", ";dump(forward<Ts>(t)...);}
#else
void dump(){}
template<class T,class... Ts> void dump(T&& h, Ts&&... t){}
#endif
template<class T> istream &operator>>(istream&is,vector<T>&v){for(auto &elemnt:v)is>>elemnt;return is;}
template<class T,class U> istream &operator>>(istream&is,pair<T,U>&p){is>>p.first>>p.second;return is;}
template<class T> ostream &operator<<(ostream& os,vector<T>const& v){for(auto const& vi:v)os<<vi<<" ";return os;}
template<class T,class U> ostream &operator<<(ostream& os,pair<T,U>const& p){os<<p.first<<","<<p.second;return os;}
template<class T>vector<T> vec(size_t a){return vector<T>(a);}
template<class T, class... Ts>auto vec(size_t a, Ts... ts){return vector<decltype(vec<T>(ts...))>(a, vec<T>(ts...));}
using vertex = struct vertex{ll to,cost;vertex(ll to,ll cost):to(to),cost(cost){}};
using edge = struct edge{ll from,to,cost;edge(ll from,ll to,ll cost):from(from),to(to),cost(cost){}};
using weighted_adjlist = vector<vector<vertex>>;
using weighted_edge = vector<edge>;
auto Dijkstra(weighted_adjlist& adj,ll S){
  ll N=(ll)adj.size();
  vector<ll> dist(N,(1LL<<60));
  vector<ll> prev_v(N,-1LL);
  using pll = pair<ll,ll>;
  priority_queue<pll,vector<pll>,greater<>> que;
  dist[S]=0LL;
  que.emplace(dist[S],S);
  while(!que.empty()){
    ll cost,from;
    tie(cost,from) = que.top();
    que.pop();
    if(dist[from]<cost)continue;
    for(const auto& v:adj[from]){
      if( chmin(dist[v.to],dist[from]+v.cost) ){
        prev_v[v.to]=from;
        que.emplace(dist[v.to],v.to);
      }
    }
  }
  return dist;
  //return prev_v;
  //return make_pair(dist,prev_v);
}
signed main(){

  ll n,m,p;
  cin>>n>>m>>p;
  ll s,g;
  cin>>s>>g;
  weighted_adjlist adj(n+1);
  rep(i,m){
    int u,v;
    cin>>u>>v;
    adj[u].emplace_back(v,1);
    adj[v].emplace_back(u,1);
  }
  auto dist_s = Dijkstra(adj,s);
  auto dist_g = Dijkstra(adj,g);

  // 1 indexed
  set<int> ans;
  for(int v=1;v<=n;++v){
    ll min_dist = dist_s[v]+dist_g[v];
    if(min_dist>p)continue;
    if((p-min_dist)%2==0){
      ans.emplace(v);
      continue;
    }
    for(auto&nv:adj[v]){
      if(dist_s[v]==dist_s[nv.to] and dist_s[v]+dist_s[nv.to]+1<=p ){
        ans.emplace(v);
        break;
      }
      if(dist_g[v]==dist_g[nv.to] and dist_g[v]+dist_g[nv.to]+1<=p){
        ans.emplace(v);
        break;
      }
    }
  }
  if(size(ans)==0){
    cout<< -1 <<endl;
    return 0;
  }
  cout<<size(ans)<<endl;
  for(auto& v:ans)cout<<v<<endl;

}