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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

public class Main {
  public static void main(final String[] args) {
    final Scanner sc = new Scanner(System.in);
    final String sNum = sc.next();
    final String[] sArray = sNum.split("");
    final List<String> listStr = new LinkedList<String>();
    boolean bResult = false;
    String sResult;
    int listSize = 0;
    int iResultCnt = 0;
    for (int ii = 0; ii < sArray.length; ii++) {

      // 小文字かどうか比較
      if (!sArray[ii].toLowerCase().equals(sArray[ii])) {
        if (ii == 0 && "A".equals(sArray[ii])) {
          bResult = true;
          continue;
        }

        // 先頭から3文字目 かつ 末尾から2文字目の間
        if (ii >= 2 && ii <= sArray.length - 2) {
          if ("C".equals(sArray[ii])) {
            iResultCnt++;
            continue;
          }
        } else {
          if ("C".equals(sArray[ii])) {
            iResultCnt++;
            continue;
          }
        }
      } else {
        listStr.add(sArray[ii]);
      }
    }
    listSize = listStr.size();
    if (bResult && 1 == iResultCnt && sArray.length - 2 == listSize) {
      sResult = "AC";
    } else {
      sResult = "WA";
    }
    System.out.print(sResult);
  }
}