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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
class p
{
  static void Main()
  {
    string s = Console.ReadLine();
    bool result = true;
    
    // Aチェック
    if (s[0] != 'A') {
      result = false;
    }
    // Cチェック
    int index = s.IndexOf("C");
    if (index < 2 || s.Length - 2 < index) {
      result = false;
    }
    // 小文字チェック
    for (int i = 1; i < s.Length; i++) {
      if (i == index) { continue; }
      if (Char.IsUpper(s[i])) {
        result = false;
        break;
      }
    }
    Console.WriteLine(result ? "AC" : "WA");
  }
}