using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[] NMi => ReadLine().Split().Select(c => int.Parse(c) - 1).ToArray();
    static int[][] NMap(int n) => Enumerable.Repeat(0, n).Select(_ => NMi).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m, p) = (c[0], c[1], c[2]);
        c = NMi;
        var (s, g) = (c[0], c[1]);
        var map = NMap(m);
        var tree = new List<int>[n];
        for (var i = 0; i < n; ++i) tree[i] = new List<int>();
        foreach (var edge in map)
        {
            tree[edge[0]].Add(edge[1]);
            tree[edge[1]].Add(edge[0]);
        }
        var (sev, sod) = GetLength(s, tree);
        var (gev, god) = GetLength(g, tree);

        var list = new List<int>();
        for (var i = 0; i < n; ++i)
        {
            if (p % 2 == 0)
            {
                if (sev[i] + gev[i] <= p || sod[i] + god[i] <= p) list.Add(i + 1);
            }
            else
            {
                if (sev[i] + god[i] <= p || sod[i] + gev[i] <= p) list.Add(i + 1);
            }
        }
        if (list.Count > 0)
        {
            WriteLine(list.Count);
            WriteLine(string.Join("\n", list));
        }
        else
        {
            WriteLine("-1");
        }
    }
    static int INF = int.MaxValue / 2;
    static (int[] ev, int[] od) GetLength(int start, List<int>[] tree)
    {
        var ev = Enumerable.Repeat(INF, tree.Length).ToArray();
        var od = Enumerable.Repeat(INF, tree.Length).ToArray();
        ev[start] = 0;
        var q = new Queue<(int pos, int len)>();
        q.Enqueue((start, 0));
        while (q.Count > 0)
        {
            var cur = q.Dequeue();
            foreach (var next in tree[cur.pos])
            {
                if (cur.len % 2 == 0)
                {
                    if (od[next] <= cur.len + 1) continue;
                    od[next] = cur.len + 1;
                    q.Enqueue((next, od[next]));
                }
                else
                {
                    if (ev[next] <= cur.len + 1) continue;
                    ev[next] = cur.len + 1;
                    q.Enqueue((next, ev[next]));
                }
            }
        }
        return (ev, od);
    }
}