Problem:
Score : 200 points

Problem Statement

Snuke has decided to construct a string that starts with A and ends with Z, by taking out a substring of a string s (that is, a consecutive part of s).

Find the greatest length of the string Snuke can construct. Here, the test set guarantees that there always exists a substring of s that starts with A and ends with Z.

Constraints

1 ≦ |s| ≦ 200{,}000

s consists of uppercase English letters.

There exists a substring of s that starts with A and ends with Z.

Input

The input is given from Standard Input in the following format:

s

Output

Print the answer.

Sample Input 1

QWERTYASDFZXCV

Sample Output 1

5

By taking out the seventh through eleventh characters, it is possible to construct ASDFZ, which starts with A and ends with Z.

Sample Input 2

ZABCZ

Sample Output 2

4

Sample Input 3

HASFJGHOGAKZZFEGA

Sample Output 3

12

Solution in OCaml (4.02.3) (judge verdict: Wrong Answer)

let s = read_line ();;
let slen = String.length s;;

let rec loop1 i en = 
    if i == slen
    then 
        en
    else
        match s.[i] with
            |'Z' -> loop1 (i+1) i
            |_ -> loop1 (i+1) en;;

let rec loop2 i = 
    match s.[i] with
    |'A' -> i,loop1 i 0
    |_ -> loop2 (i+1);;


let (st,en) = loop2 0
    in
        Printf.printf "%s\n" (String.sub s st (en-st+1)) ;;