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 Haskell (GHC 7.10.3) (judge verdict: Accepted)

main = do
  s <- getLine 
  putStrLn $ solve s

solve :: String -> String 
solve s = if bool1 s && bool2 s && bool3 s then "AC" else "WA"

isLower :: Char -> Bool 
isLower c = if 'a' <= c && c <= 'z' then True else False

bool1 :: String -> Bool
bool1 (x:xs) = and $ map isLower target
  where target = filter (\c -> c /= 'C') xs

bool2 :: String -> Bool
bool2 ('A':rest) = True
bool2 _ = False

bool3 :: String -> Bool
bool3 s = if (length $ filter (\c -> c == 'C') substr) == 1 then True else False
  where substr = init.tail.tail $ s