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.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    
    //条件１
    boolean j1 = false;
    if('A' == s.charAt(0)){
      j1 = true;
    }
    
    //条件２
    boolean j2 = false;
    for(int i = 2 ; i < s.length()-1 ; ++i){
      if('C' == s.charAt(i) && j2 == false){
        j2 = true;
      }else if('C' == s.charAt(i) && j2 == true){
        j2 = false;
        break;
      }
    }

    //条件３
    boolean j3 = false;
    for(int i = 0 ; i < s.length() ; ++i){
      if('A' == s.charAt(i)){
        j3 = true;
      }else if('C' == s.charAt(i)){
        j3 = true;
      }else if(Character.isUpperCase(s.charAt(i))==false){
        j3 = true;
      }else{
        j3 = false;
        break;
      }
    }
    
    if(j1&&j2&&j3){
      System.out.println("AC");
    }else{
      System.out.println("WA");
    }
    
  }
}