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;

namespace B
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = Console.ReadLine();
            bool cf = false;
            bool f = true;
            if (str[0] == 'A' && char.IsLower(str[1]) && char.IsLower(str.Last()))
            {
                foreach (char c in str.Substring(2,str.Length - 3))
                {
                    if (c == 'C')
                    {
                        if (!cf)
                            cf = true;
                        else
                        {
                            f = false;
                            break;
                        }
                    }
                    else if (char.IsUpper(c))
                    {
                        f = false;
                        break;
                    }
                }
            }

            if (cf && f)
            {
                Console.WriteLine("AC");
            }
            else
            {
                Console.WriteLine("WA");
            }
#if DEBUG
            Console.ReadKey();
#endif
        }
    }
}