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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
class Abc
{
    static void Main()
    {
        string N = Console.ReadLine();
        int CC = 0;
        for (int i = 0; i < N.Length; i++)
        {
            if (char.IsUpper(N, i)) CC += 1;
        }
        if (N.Substring(N.Length-1) == "C" || N.Count(c => c == 'C') >= 2 ||  CC >= 3) Console.WriteLine("WA");
        else if (N.Substring(0, 1) == "A" && 2 <= N.IndexOf("C") && N.IndexOf("C") <= N.Length - 1) Console.WriteLine("AC");
        else Console.WriteLine("WA");
    }

}