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.strip

c_found = false
s.chars.each_with_index{|v, i|
  if i == 0 
    if v != 'A'
      puts "WA"
      exit
    end
    next
  end
  if i == 1 || i == s.length - 1
    if !v.match(/[a-z]/)
      puts "WA"
      exit
    end
    next
  end
  if v == 'C'
    if !c_found
      c_found = true
    else
      puts "WA"
      exit
    end
  else
    if !v.match(/[a-z]/)
      puts "WA"
      exit
    end
  end
}

if c_found
  puts "AC"
else
  puts "WA"
end