object Main extends App {
  val sc = new java.util.Scanner(System.in)
  val n = sc.nextInt
  var a = Seq.fill(n)(sc.nextLong)
  while (a.length > 1) {
    a = a.zip(a.drop(1)).map(i => (i._1 + i._2) % 1000000007)
  }
  println(a(0))
}