Problem:
Score : 100 points

Problem Statement

CODE FESTIVAL 2016 is going to be held. For the occasion, Mr. Takahashi decided to make a signboard.

He intended to write CODEFESTIVAL2016 on it, but he mistakenly wrote a different string S. Fortunately, the string he wrote was the correct length.

So Mr. Takahashi decided to perform an operation that replaces a certain character with another in the minimum number of iterations, changing the string to CODEFESTIVAL2016.

Find the minimum number of iterations for the rewrite operation.

Constraints

S is 16 characters long.

S consists of uppercase and lowercase alphabet letters and numerals.

Input

Inputs are provided from Standard Input in the following form.

S

Output

Output an integer representing the minimum number of iterations needed for the rewrite operation.

Sample Input 1

C0DEFESTIVAL2O16

Sample Output 1

2

The second character 0 must be changed to O and the 14th character O changed to 0.

Sample Input 2

FESTIVAL2016CODE

Sample Output 2

16

Solution in OCaml (4.02.3) (judge verdict: Accepted)

module String = struct
  include String
  let to_list s =
    let rec loop acc = function
      | 0 -> acc
      | n -> loop (s.[n - 1] :: acc) (n - 1) in
    loop [] (String.length s)
end

let () =
  read_line ()
  |> String.to_list
  |> List.map2 ( <> ) (String.to_list "CODEFESTIVAL2016")
  |> List.filter (fun x -> x)
  |> List.length
  |> Printf.printf "%d\n"