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)

s = gets.chomp
res = 'AC'

def lower?(c)
  if 'a' <= c
    return true
  end

  return false
end

if s[0] != 'A' || !lower?(s[1]) || !lower?(s[s.length-1])
  res = 'WA'
end

cnt = 0
c = ''

(2..s.length-2).each do |i|
  if !lower?(s[i])
    cnt += 1
    c = s[i]
  end
end

if cnt != 1 || c != 'C'
  res = 'WA'
end

puts res