#D3534. Z Cat
Z Cat
Z Cat
A: A-Z Cat / A-Z Cat
story
Aizunyan is a second-year student who belongs to the programming contest club of Wakagamatsu High School, commonly known as the Prokon club. It's so cute. Aizu Nyan was asked by her friend Joy to take care of her cat. It is a rare cat called A-Z cat. Aizunyan named the A-Z cat he had entrusted to him as "Aizunyan No. 2" (without permission), and he was very much loved.
A-Z cats are said to prefer strings that meet certain conditions. Then, when Aizunyan gave a character string as a trial, Aizunyan No. 2 had a satisfying expression after cutting a part of the character string with his nails. Apparently, I'm trying to rewrite it to my favorite character string.
D, who is crazy about Aizu Nyan, who is cute like an angel, found out the character string conditions that A-Z Cat likes for Aizu Nyan. It is a string in which'A'and'Z'are repeated alternately, and a string that starts with'A' and ends with'Z'. The A-Z cat is so smart that it tries to convert it to a string of your choice with minimal erasing. D, who wants to look good, decided to write a program to find out what kind of string the A-Z cat would convert from a given string consisting only of'A'and'Z'.
problem
Given a string S consisting only of uppercase letters. By deleting any number of S characters as much as you like, you can create a string in which'A'and'Z' appear alternately, and start with'A' and end with'Z'. Find the character string obtained when the number of deletions is minimized.
Input format
The string S is given on one line as input. S consists of uppercase letters only and satisfies 1 ≤ | S | ≤ 20.
Output format
Output the string that is obtained by deleting the minimum number of characters for S, in which'A'and'Z' appear alternately, and start with'A' and end with'Z' on one line. If no character string that meets the conditions is obtained by deleting any character, output -1 on one line.
Input example 1
AIZUNYAN PEROPERO
Output example 1
AZ
Input example 2
AZAZ
Output example 2
AZAZ
Input example 3
ZDDYAZAWABDDZAZPIDDA
Output example 3
AZAZAZ
Input example 4
ZZZZAAAAAA
Output example 4
-1
Example
Input
AIZUNYANPEROPERO
Output
AZ
inputFormat
Input format
The string S is given on one line as input. S consists of uppercase letters only and satisfies 1 ≤ | S | ≤ 20.
outputFormat
Output format
Output the string that is obtained by deleting the minimum number of characters for S, in which'A'and'Z' appear alternately, and start with'A' and end with'Z' on one line. If no character string that meets the conditions is obtained by deleting any character, output -1 on one line.
Input example 1
AIZUNYAN PEROPERO
Output example 1
AZ
Input example 2
AZAZ
Output example 2
AZAZ
Input example 3
ZDDYAZAWABDDZAZPIDDA
Output example 3
AZAZAZ
Input example 4
ZZZZAAAAAA
Output example 4
-1
Example
Input
AIZUNYANPEROPERO
Output
AZ
样例
AIZUNYANPEROPEROAZ