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

$a = trim(fgets(STDIN));

$a1 = substr($a,0,1);


if("A" !== $a1){
  echo "WA\n";
  return;
}

$a2 = substr($a,2,-1);

// if(strlen($a2) - strlen(str_replace("C","",$a2)) != 1){
if(substr_count($a2, "C") != 1){
  echo "WA\n";
  return;
}

$a3 = str_replace("C","c",$a2) .  substr($a,1,1) . substr($a,-1,1);
// echo $a3;

if(!ctype_lower($a3)){
  echo "WA\n";
  return;
}

echo "AC\n";