Problem:
Score : 200 points

Problem Statement

You are given a string S. Each character of S is uppercase or lowercase English letter.
Determine if S satisfies all of the following conditions:

The initial character of S is an uppercase A.

There is exactly one occurrence of C between the third character from the beginning and the second to last character (inclusive).

All letters except the A and C mentioned above are lowercase.

Constraints

4 ≤ |S| ≤ 10 (|S| is the length of the string S.)

Each character of S is uppercase or lowercase English letter.

Input

Input is given from Standard Input in the following format:

S

Output

If S satisfies all of the conditions in the problem statement, print AC; otherwise, print WA.

Sample Input 1

AtCoder

Sample Output 1

AC

The first letter is A, the third letter is C and the remaining letters are all lowercase, so all the conditions are satisfied.

Sample Input 2

ACoder

Sample Output 2

WA

The second letter should not be C.

Sample Input 3

AcycliC

Sample Output 3

WA

The last letter should not be C, either.

Sample Input 4

AtCoCo

Sample Output 4

WA

There should not be two or more occurrences of C.

Sample Input 5

Atcoder

Sample Output 5

WA

The number of C should not be zero, either.

Solution in PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php

$S = trim(fgets(STDIN));

if($S[0]!='A' || ctype_upper($S[1]) || ctype_upper($S[strlen($S)-1])){
    echo 'WA';
    exit;
}

$ok = false;
for($i=2;$i<strlen($S);$i++) {
    if($S[$i] == 'C'){
        $ok = true;
        continue;
    }
    if(ctype_upper($S[$i])) {
        echo 'WA';
        exit;
    }
}

echo $ok ? 'AC' : 'WA';