#include <bits/extc++.h>

#ifndef DUMP
#define DUMP(...) (void)0
#endif

using namespace std;

struct graph {
  struct edge {
    int src, dst;
    int operator-(int v) const { return src ^ dst ^ v; }
  };
  int n, m;
  vector<edge> edges;
  vector<vector<pair<int, int>>> adj;
  graph(int _n = 0) : n(_n), m(0), adj(n) {}
  int add(const edge& e, bool directed = false) {
    edges.push_back(e);
    adj[e.src].emplace_back(m, e.dst);
    if (not directed) adj[e.dst].emplace_back(m, e.src);
    return m++;
  }
};

vector<int> bfs(const graph& g, int s) {
  vector d(g.n, 0x3f3f3f3f);
  queue<int> que;
  d[s] = 0;
  que.push(s);
  while (not empty(que)) {
    int v = que.front();
    que.pop();
    for (auto [id, u] : g.adj[v])
      if (d[u] == 0x3f3f3f3f) {
        d[u] = d[v] + 1;
        que.push(u);
      }
  }
  return d;
}

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n, m, p;
  cin >> n >> m >> p;
  int s, t;
  cin >> s >> t;
  --s, --t;
  graph g(n * 2);
  while (m--) {
    int u, v;
    cin >> u >> v;
    --u, --v;
    g.add({u * 2, v * 2 + 1});
    g.add({u * 2 + 1, v * 2});
  }
  auto ds = bfs(g, s * 2);
  if (ds[t * 2 + (p & 1)] > p) {
    cout << "-1\n";
    exit(0);
  }
  auto dt = bfs(g, t * 2);
  vector<int> res;
  for (int v = 0; v < n; ++v) {
    for (int x : {0, 1}) {
      if (ds[v * 2 + x] + dt[v * 2 + ((p & 1) ^ x)] <= p) {
        res.push_back(v);
        break;
      }
    }
  }
  cout << size(res) << '\n';
  for (auto&& e : res) cout << e + 1 << '\n';
}