open Num

let solve k darr =
  let len_darr = Array.length darr in
  let chk_darr = Array.make len_darr false in

  let rec get_len_loop start current result =
    chk_darr.(current) <- true;

    let next = darr.(current) in

    if next = start then result
    else get_len_loop start next (result + 1)
  in

  let rec get_len_loop_sum idx result =
    if idx >= len_darr then result
    else (
      if chk_darr.(idx) then get_len_loop_sum (idx + 1) result
      else
        let len_loop = get_len_loop idx idx 0 in
        get_len_loop_sum (idx + 1) (result + len_loop)
    )
  in

  let len_loop = get_len_loop_sum 0 0 |> num_of_int in
  k >=/ len_loop && mod_num (k -/ len_loop) (Int 2) = (Int 0)

let () =
  let k = read_line ()
          |> fun l -> Scanf.sscanf l "%s %s" (fun s1 s2 -> num_of_string s2)
  and darr = read_line ()
             |> Str.split (Str.regexp_string " ")
             |> List.map int_of_string
             |> List.map (( + ) (-1))
             |> Array.of_list
  in
	solve k darr
	|> (function | true -> "YES" | false -> "NO")
	|> print_endline