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.Scanner;
import java.util.regex.Pattern;

public class Main {

    static Scanner sc = new Scanner(System.in);


    public static void main(String[] args) {
        String s = sc.next();
        boolean result = false;

        int indexC = s.indexOf("C");

        if ("A".equals(s.substring(0, 1)) && indexC >= 2 && indexC < s.length() - 2 && !onemoretime(s, 'C')) {
            s = s.replace("A", "");
            s = s.replace("C", "");
            String pattern = "^[a-z]+$";
            Pattern p = Pattern.compile(pattern);
            if (p.matcher(s).find()) {
                result = true;
            }
        }
        System.out.println(result ? "AC" : "WA");

    }

    static boolean onemoretime(String str, char target) {
        return str.length() - str.replace(target + "", "").length() > 1;
    }
}