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 PHP (5.6.30) (judge verdict: Wrong Answer)

<?php
  
 $S = fgets(STDIN);
 $_S = str_split($S);
 $count =0;
 $count_c = 0;
 $len = strlen($S);
 if($_S[0] !== "A"){die("WA");}
 foreach($_S as $val){
   if($count > 2 && $count < ($len -2)){
     if(strtoupper($val) === $val || $val === "C"){die("WA");}
   }else{
     if($val === "C"){
      if($count_c === 0){$count_c++;}else{die("WA");}
     }else{
      if(strtoupper($val) === $val){die("WA");}
     }
   }
   $count++;
 }
 if($count_c === 0){
   die("WA");
 }
?>