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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {

  public static void main(String[] args) {

    Scanner sc = new Scanner(System.in);

    String s = sc.next();
    boolean ok = true;

    if (s.charAt(0) != 'A') {
      ok = false;
    }

    boolean cok = true;
    for (int i = 2; i < (s.length() - 1); i++) {
      if (s.charAt(i) == 'C') {
        if (!cok) {
          ok = false;
        } else {
          cok = false;
        }
      }
    }

    if (cok) {
      ok = false;
    }

    for (int i = 0; i < s.length(); i++) {
      char c = s.charAt(i);
      if ((c != 'A') && (c != 'C')) {
        if (!(('a' <= c) && (c <= 'z'))) {
          ok = false;
        }
      }
    }

    if (ok) {
      System.out.println("AC");
    } else {
      System.out.println("WA");
    }

  }
}