import java.io.FileInputStream
import java.nio.file.Files
import java.nio.file.Paths
import java.util.*
import kotlin.collections.ArrayList

class Task {
    private val n: Int
    private val m: Int
    private val graph: MutableList<MutableList<Int>>
    private val used: MutableList<Int>
    private val ans: MutableList<Int>

    constructor() {
        val scan: Scanner = Scanner(FileInputStream("cycle.in"))
        n = scan.nextInt()
        m = scan.nextInt()
        graph = ArrayList()
        used = ArrayList()
        ans = ArrayList()
        for (i in 0 until n) {
            graph.add(ArrayList())
            used.add(0)
        }
        for (i in 0 until m) {
            val from = scan.nextInt()
            val to = scan.nextInt()
            graph[from - 1].add(to - 1)
        }
    }

    fun dfs(vert: Int): Boolean {
        used[vert] = 1
        ans.add(vert)
        for (a in graph[vert]) {
            if (used[a] == 0) {
                if (dfs(a)) return true
            } else {
                if (used[a] == 1) {
                    ans.add(a)
                    return true
                }
            }
        }
        ans.removeAt(ans.size - 1)
        used[vert] = 2
        return false
    }

    fun findCycle() {
        val bf = Files.newBufferedWriter(Paths.get("cycle.out"))
        for (i in 0 until n) {
            if (used[i] == 0) {
                if (dfs(i)) {
                    bf.write("YES"+System.lineSeparator())
                    var counter = 2
                    var cur : Int = ans[ans.size -counter]
                    while (cur != ans.last()){
                        bf.write((cur + 1).toString() + " ")
                        counter++
                        cur = ans[ans.size - counter]
                    }
                    bf.write((cur + 1).toString())
                    bf.close()
                    return
                }
            }
        }
        bf.write("NO")
        bf.close()

    }

}

fun main() {
    val task = Task()
    task.findCycle()
}