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.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) {
    	FastScanner sc = new FastScanner(System.in);
    	String str = sc.nextToken();
    	char[] s = str.toCharArray();
    	boolean flag = true, existC = false;
    	if(s.length < 4 || s.length > 10 || s[0] != 'A')
    		flag = false;
    	for(int i = 1; i < s.length && flag; ++i) {
    		if(s[i] <= 'z' && s[i] >= 'a')
    			continue;
    		else if(s[i] == 'C') {
    			if(!existC && i > 1 && i < s.length-1)
    				existC = true;
    			else
    				flag = false;
    		} else {
				flag = false;
			}
    	}
    	if(flag && existC)
    		System.out.println("AC");
    	else
    		System.out.println("WA");
    }
}

class FastScanner {
    BufferedReader br;
    StringTokenizer st;
    boolean hasNext;

    public FastScanner(InputStream is) {
        br = new BufferedReader(new InputStreamReader(is));
        hasNext = true;
    }

    public String nextToken() {
        while (st == null || !st.hasMoreTokens()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                hasNext = false;
                return "##";
            }
        }
        return st.nextToken();
    }

    String next = null;
    public boolean hasNext(){
        next = nextToken();
        return hasNext;
    }

    public int nextInt() {
        if (next == null){
            hasNext();
        }
        String more = next;
        next = null;
        return Integer.parseInt(more);
    }

    public long nextLong() {
        if (next == null){
            hasNext();
        }
        String more = next;
        next = null;
        return Long.parseLong(more);
    }

    public double nextDouble() {
        if (next == null){
            hasNext();
        }
        String more = next;
        next = null;
        return Double.parseDouble(more);
    }

    public String nextString(){
        if (next == null){
            hasNext();
        }
        String more = next;
        next = null;
        return more;
    }

    public char nextChar(){
        if (next == null){
            hasNext();
        }
        String more = next;
        next = null;
        return more.charAt(0);
    }
}