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 Ruby (2.3.3) (judge verdict: Accepted)

def isup(s)
  /[[:upper:]]/.match(s)
end

S=gets.strip
if S[0]!='A'
  puts 'WA'
  exit
end

a=[]
a<<0

ok=false
(2..S.size-2).each do |i|
  if S[i]=='C'
    ok=true
    a<<i
  end
end

if !ok || a.size!=2
  puts 'WA'
  exit
end

(0..S.size-1).each do |i|
  if !a.include?(i) && isup(S[i])
    puts 'WA'
    exit
  end
end

puts 'AC'