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 Rust (1.15.1) (judge verdict: Accepted)

use std::thread;

/// ローカル環境なら _in.txt から入力を受ける
fn read_input() -> String {
    use std::fs::File;
    use std::io::Read;
    let mut s = String::new();
    match option_env!("LOCAL") {
        Some(_) => File::open("src/_in.txt")
            .expect("File not found")
            .read_to_string(&mut s)
            .unwrap(),
        None => std::io::stdin().read_to_string(&mut s).unwrap(),
    };
    s
}

fn main() {
    thread::Builder::new()
        .stack_size(32 * 1024 * 1024) // 32MB
        .spawn(run)
        .unwrap()
        .join()
        .unwrap();
}

fn run() {
    let input = read_input();
    let mut input = input.split_whitespace();
    let in_s = input.next().unwrap();
    let ans: Vec<char> = "CODEFESTIVAL2016".chars().collect();
    let mut wrong = 0;
    for (i, c) in in_s.chars().enumerate() {
        if c != ans[i] {
            wrong += 1;
        };
    }
    println!("{:?}", wrong);
}