open Printf
open Scanf

let is_palindrome s =
  let l = String.length s in
  let rec loop i =
    if i = l / 2 then true
    else if s.[i] = s.[l-1-i] then loop (i + 1)
    else false
  in loop 0

let solve s =
  if is_palindrome s && is_palindrome (String.sub s 0 (String.length s / 2)) then "Yes" else "No"

let () =
  scanf "%s " solve |> printf "%s\n"
