let read_int_array n = Array.init n (fun _ -> Scanf.scanf " %d" (fun x -> x))

let n, a, b = Scanf.scanf "%d %d %d" (fun n a b -> n, a, b)
let x = read_int_array n

let rec ans i ret =
  if i = n - 1 then ret
  else ans (i + 1) (ret + min (a * (x.(i+1) - x.(i))) b)

let () = print_int (ans 0 0) 