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 (4.10.0) (judge verdict: Accepted)

Scanf.scanf "%s" (fun s ->
    let rec loop i acc =
        if i = 16 then acc else
            let acc = if s.[i] <> "CODEFESTIVAL2016".[i] then acc + 1 else acc in
            loop (i + 1) acc
    in
    loop 0 0 |> Printf.printf "%d\n"
)