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;

namespace AtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            MainStream();
        }
        static void MainStream()
        {
            char[] s = Console.ReadLine().ToCharArray();
            if(Judge(s))
            {
                Console.WriteLine("AC");
            }
            else
            {
                Console.WriteLine("WA");
            }

        }
        static bool Judge(char[] s)
        {
            int C_count = 0;
            int C_index = 0;
            if (s[0] != 'A')
            {
                return false;
            }
            for (int i = 2; i < s.Length - 1; i++)
            {
                if (s[i] == 'C')
                {
                    C_count += 1;
                    C_index = i;

                    if(C_count > 1)//Cが二個以上
                    {
                        return false;
                    }

                }
            }
            if(C_count != 1)
            {
                return false;
            }
            for (int i = 1;i<s.Length;i++)
            {
                if (i != C_index)
                {
                    if (Char.IsUpper(s[i]))
                    {
                        return false;
                    }
                }
            }
            return true;
        }


    }
}