import java.io.{BufferedOutputStream, BufferedReader, InputStreamReader, PrintWriter}

object Main {
  def main(args: Array[String]): Unit = {
    val in = new BufferedReader(new InputStreamReader(System.in))
    val out = new PrintWriter(new BufferedOutputStream(System.out))
    val Array(n, m) = in.readLine().split("\\s+").map(_.toInt)

    val vertices = Array.fill(n + 1)(0)

    for (i <- 0 until m) {
      in.readLine().split("\\s+").map(_.toInt) match {
        case Array(a, b) =>
          vertices(a) = (vertices(a) + 1) % 2
          vertices(b) = (vertices(b) + 1) % 2
      }
    }

    out.println(
      if (vertices.forall(_ == 0)) {
        "YES"
      } else {
        "NO"
      }
    )

    out.flush()
  }
}