import scala.annotation.tailrec
import scala.collection.mutable
import scala.io.StdIn._
object Main extends App {

  val Array(n, m) = readLine.trim.split(' ').map(_.toInt)
  val nodes = Array.tabulate(n){_ ⇒ Nil: List[Edge]}
  for (i ← 0 until m){
    val Array(a, b) = readLine.trim.split(' ').map(_.toInt - 1)
    nodes(a) ::= Edge(i, b)
    nodes(b) ::= Edge(i, a)
  }
  println(
    if (dfs(nodes)) "Yes" else "No"
  )

  def dfs(nodes: Array[List[Edge]]): Boolean = {
    val searching = Array.tabulate(n){_ ⇒ false}
    val use = Array.tabulate(m){_ ⇒ false}
    @tailrec
    def sub(prev: Int, current: Int, path: List[Int]): Int= {
      if (searching(current)) {
        path.foreach(i ⇒ searching(i) = false)
        current
      }
      else {
        searching(current) = true
        nodes(current).dropWhile(e ⇒ e.to == prev || use(e.id)) match {
          case h::_ ⇒ sub(current, h.to, current::path)
          case Nil ⇒ -1
        }
      }
    }
    def remove(start: Int): Unit = {
      nodes(start).dropWhile(e ⇒ use(e.id)) match {
        case h::t ⇒
          use(h.id) = true
          nodes(start) = t
          sub(h.to)
          nodes(start) = nodes(start).dropWhile(e ⇒ use(e.id))
        case Nil ⇒ ???
      }
      @tailrec
      def sub(current: Int): Unit = {
        if (current != start){
          nodes(current).dropWhile(e ⇒ use(e.id)) match {
            case h::t ⇒
              use(h.id) = true
              nodes(current) = t
              sub(h.to)
            case Nil ⇒ ???
          }
        }
      }
    }
    var count = 0
    for (i ← 0 until n if count >= 0){
      var start = 0
      nodes(i) = nodes(i).dropWhile(e ⇒ use(e.id))
      while(nodes(i).nonEmpty && start != -1){
        start = sub(-1, i, Nil)
        if (start != -1){
          remove(start)
          count += 1
        }
      }
      if (nodes(i).nonEmpty){
        count = -1
      }
    }
    count >= 3
  }

  case class Edge(id: Int, to: Int)
  implicit class Extension[T](val value: T) extends AnyVal {
    @inline def let[A](@inline func: T ⇒ A): A = func(value)
    @inline def also(@inline func: T ⇒ Unit): T = {func(value); value}
  }
}