object Main extends App {
  val sc = new java.util.Scanner(System.in)
  val n = sc.nextInt()
  val a, b = sc.nextLong()
  val x = List.fill(n)(sc.nextLong())
  val ans = x.sliding(2).map{ case List(x1, x2) =>
    ((x2 - x1) * a).min(b)
  }.sum
  println(ans)
}
