#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

struct Node {
  int v;
  int dist;

  Node(int v = -1, int dist = -1) {
    this->v = v;
    this->dist = dist;
  }

  bool operator>(const Node &n) const {
    return dist > n.dist;
  }
};

int main() {
  int N, M, P;
  cin >> N >> M >> P;
  int S, G;
  cin >> S >> G;

  vector<int> E[N + 1];
  for (int i = 0; i < M; ++i) {
    int u, v;
    cin >> u >> v;

    E[u].push_back(v);
    E[v].push_back(u);
  }

  int min_distance[2][N + 1][2];
  memset(min_distance, -1, sizeof(min_distance));

  for (int i = 0; i < 2; ++i) {
    int root = (i == 0) ? S : G;

    queue<Node> que;
    que.push(Node(root, 0));
    bool visited[N + 1][2];
    memset(visited, false, sizeof(visited));

    while (not que.empty()) {
      Node node = que.front();
      que.pop();
      int t = node.dist % 2;

      if (visited[node.v][t]) continue;
      visited[node.v][t] = true;
      min_distance[i][node.v][t] = node.dist;

      for (int u : E[node.v]) {
        que.push(Node(u, node.dist + 1));
      }
    }
  }

  vector<int> ans;

  for (int v = 1; v <= N; ++v) {
    int d1 = INT_MAX;
    int d2 = INT_MAX;

    if (P % 2 == 0) {
      if (min_distance[0][v][0] != -1 && min_distance[1][v][0] != -1) {
        d1 = min_distance[0][v][0] + min_distance[1][v][0];
      }
      if (min_distance[0][v][1] != -1 && min_distance[1][v][1] != -1) {
        d2 = min_distance[0][v][1] + min_distance[1][v][1];
      }
    } else {
      if (min_distance[0][v][0] != -1 && min_distance[1][v][1] != -1) {
        d1 = min_distance[0][v][0] + min_distance[1][v][1];
      }
      if (min_distance[0][v][1] != -1 && min_distance[1][v][0] != -1) {
        d2 = min_distance[0][v][1] + min_distance[1][v][0];
      }
    }
    // fprintf(stderr, "v: %d, d1: %d, d2: %d\n", v, d1, d2);
    if ((d1 <= P && (P - d1) % 2 == 0) || (d2 <= P && (P - d2) % 2 == 0)) {
      ans.push_back(v);
    }
  }

  if (ans.empty()) {
    cout << -1 << endl;
  } else {
    cout << ans.size() << endl;
    for (int v : ans) {
      cout << v << endl;
    }
  }

  return 0;
}