
import java.util.Scanner

/**
 * Created by sonetsuyoshi on 2015/12/16.
 */

object Main extends App {
  val sc = new Scanner(System.in)
  val (n, m) = (sc.nextInt, sc.nextInt)

  val edges = for(i <- 0 until m) yield (sc.nextInt - 1, sc.nextInt - 1)

  val counts = new Array[Int](n)

  edges.foreach { case (x, y) => {
    counts(x) += 1
    counts(y) += 1
  }}
  if(counts.forall(_ % 2 == 0)) println("YES")
  else println("NO")
}
