import scala.io.StdIn

object Main {
  def main(args: Array[String]): Unit = {
    val d = StdIn.readInt
    val b = StdIn.readLine.split(' ').map(_.toInt).toArray
    val sz = b.size

    for (i <- (3 to d).reverse) {
      b(i - 2) += b(i)
      b(i) = 0
    }

    val dd = if (d >= 2 && b(2) != 0) {
      2
    } else if (d >= 1 && b(1) != 0) {
      1
    } else {
      0
    }

    println(dd)
    println(b.slice(0, dd + 1).mkString(" "))
  }
}