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: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

class Program
{
    static void Main()
    {
        string S = Console.ReadLine();
        string OutputString;

        if(S[0] != 'A')
        {
            Console.WriteLine("WA");
            return;
        }

        int CountC = 0;
        int PlaceC = 0;
        for(int i = 3; i < S.Length - 2;i++)
        {
            if(S[i] == 'C')
            {
                CountC++;
                PlaceC = i;
            }
        }

        if(CountC != 1)
        {
            Console.WriteLine("WA");
            return;
        }

        for(int i = 0; i < S.Length; i++)
        {
            if(i == 0 || i == PlaceC)
            {
                continue;
            }

            if(S[i] < 'a' || 'z' < S[i])
            {
                Console.WriteLine("WA");
                return;
            }
        }

        Console.WriteLine("AC");
    }
}