import scala.io.StdIn.readLine

object Main extends App {
  val Array(n, a, b) = readLine.split(" ").map(_.toInt)
  val xs = readLine.split(" ").map(_.toInt)

  val ds = for(Array(a, b) <- xs.sliding(2)) yield (b - a).toLong
  val mincs = ds.map(_ * a min b)

  println(mincs.sum)
}
