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) throws Exception {
        
        
        Scanner sc = new Scanner(System.in);
		String s = sc.next();
		
		if (s.charAt(0)!='A') {
		    
			System.out.println("WA");
			return ;
			
		}
		int count =0;
		for (int i=2;i<s.length()-1;i++) {
		    
			if (s.charAt(i)=='C') {
			    
				count ++;
			}
		}
		
		if (count!=1) {
			System.out.println("WA");
			return ;
		}
		
		for (int i=1;i<s.length();i++) {
		    
			if (s.charAt(i)!='C'&&(s.charAt(i)<'a'||s.charAt(i)>'z')) {
				System.out.println("WA");
				return ;
			}
			
			if (s.charAt(i)=='C') {
				if (i==1||i==s.length()-1) {
				    
					System.out.println("WA");
					return ;
				}
			}
		}
		
		System.out.println("AC");
		return ;
	}
}