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

namespace ABC_Training
{
    class Program
    {
        static void Main(string[] args)
        {
            var s = Console.ReadLine();
            if (IsAC(s))
            {
                Console.WriteLine("AC");
            }
            else
            {
                Console.WriteLine("WA");
            }
        }

        private static bool IsAC(string s)
        {
            return IsStartA(s) && ContainsC(s) && OneA(s) && OneC(s) && Small(s);
        }

        private static bool Small(string s)
        {
            var current = s.Where(x => x != 'A' && x != 'C');
            if(current.Count() == 0)
            {
                return false;
            }
            return current.All(x => char.IsLower(x));
            

        }

        private static bool OneC(string s)
        {
            return s.Length - s.Count(x => x != 'C') == 1;
        }

        private static bool OneA(string s)
        {
            return s.Length - s.Count(x => x != 'A') == 1;
        }



        private static bool ContainsC(string s)
        {
            var sl = s.Length;
            var currentString = s.Skip(2).Take(sl - 3);
            return currentString.Any(x => x == 'C') ;
        }

        private static bool IsStartA(string s)
        {
            return s[0] == 'A';
        }
    }
}