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: Accepted)

<?php

function input_and_explode() {
    $input_line = trim(fgets(STDIN));
    return explode(" ", $input_line);
}

$S = input_and_explode()[0];
$S = str_split($S);
list($cond_1, $cond_2, $cond_3) = array(false, false, false);
$count_C = 0;
$count_small = 0;

if ($S[0] === 'A') {
    $cond_1 = true;
}

if (in_array('C', array_slice($S, 2, count($S) - 3))) {
    $cond_2 = true;
}

for ($i = 0, $len = count($S); $i < $len; $i++) {
    if (ctype_lower($S[$i])) {
        $count_small++;
    }
}

if ($count_small === count($S) - 2) {
    $cond_3 = true;
}

if ($cond_1 && $cond_2 && $cond_3) {
    $state = 'AC';
} else {
    $state = 'WA';
}

echo "$state\n";