import java.io.BufferedReader
import java.io.InputStream
import java.io.InputStreamReader
import java.io.PrintWriter
import java.util.*

fun PrintWriter.solve(sc: FastScanner) {
    val n = sc.nextInt()
    val m = sc.nextInt()
    val p = sc.nextInt()
    val s = sc.nextInt() - 1
    val g = sc.nextInt() - 1
    val adj = Array(n) { mutableSetOf<Int>() }
    for (i in 0 until m) {
        val v1 = sc.nextInt() - 1
        val v2 = sc.nextInt() - 1
        adj[v1].add(v2)
        adj[v2].add(v1)
    }
    val dist = IntArray(n) { 0 }
    val que: Queue<Pair<Int, Int>> = ArrayDeque()
    val visited = BooleanArray(n) { false }
    visited[s] = true
    que.add(s to 0)
    while (que.count() > 0) {
        val (v, step) = que.poll()
        dist[v] = step
        for (w in adj[v]) {
            if (visited[w]) continue
            que.add(w to step + 1)
            visited[w] = true
        }
    }
    if (p % 2 != dist[g] % 2 || dist[g] > p) {
        println(-1)
        return
    }
    val dist2 = IntArray(n) { 0 }
    que.clear()
    que.add(g to 0)
    for (i in 0 until n) {
        visited[i] = i == g
    }
    while (que.count() > 0) {
        val (v, step) = que.poll()
        dist2[v] = step
        for (w in adj[v]) {
            if (visited[w]) continue
            que.add(w to step + 1)
            visited[w] = true
        }
    }
    val lst = mutableListOf<Int>()
    for (i in 0 until n) {
        if (dist[i] + dist2[i] <= p) {
            lst.add(i + 1)
        }
    }
    println(lst.count())
    println(lst.joinToString("\n"))
}

fun main() {
    val writer = PrintWriter(System.out, false)
    writer.solve(FastScanner(System.`in`))
    writer.flush()
}

class FastScanner(s: InputStream) {
    private var st = StringTokenizer("")
    private val br = BufferedReader(InputStreamReader(s))

    fun next(): String {
        while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())

        return st.nextToken()
    }

    fun nextInt() = next().toInt()
    fun nextLong() = next().toLong()
    fun nextLine() = br.readLine()
    fun nextDouble() = next().toDouble()
    fun ready() = br.ready()
}