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: Accepted)


import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String S = sc.next();

        if (S.charAt(0) == 'A') {
            System.out.println(judge(S) ? "AC" : "WA");
        } else {
            System.out.println("WA");
        }
    }

    private static boolean judge(String str) {
        for (char c : str.toCharArray()) {
            for (int ct = 'D'; ct <= 'Z'; ct++) {
                if (c == (char) ct) {
                    return false;
                }
            }
            if (c == 'B') {
                return false;
            }

        }
        str = str.substring(2);
        if (str.charAt(str.length() - 1) == 'C') {
            return false;
        } else if (str.contains("C")) {
            str = str.substring(0, str.length() - 1);
            return (str.indexOf("C") == str.lastIndexOf("C"));
        } else {
            return false;
        }
    }
}