object Main {
  import scala.math
  def main(args: Array[String]) {
    val sc = new java.util.Scanner(System.in)
    val m,n = sc.nextInt
    val list = List.fill(n)(sc.nextInt)
    //print(list)
    val list2 = list.sorted.reverse
    //print(list)
    if (m-list2(0)-list2(1)>0) println("No") else println("Yes")
  }
}
