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;
class Program
 {
   static void Main(string[] args)
   {
     string s;
     s = Console.ReadLine();
     bool CFlag = false;

     for (int i = 0; i < s.Length; i++)
     {
       if(i==0)
       {
         if(s[i]!='A')
         {
           Console.WriteLine("WA");
           break;
         }
       }else if(i==1)
       {
         if(Char.IsUpper(s[i]))
         {
           Console.WriteLine("WA");
           break;
         }
         
       }else if(i==s.Length-1)
       {
         if(!CFlag||Char.IsUpper(s[i]))
         {
           Console.WriteLine("WA");
           break;
         }
         
         Console.WriteLine("AC");
      
       }else
       {
         if(Char.IsUpper(s[i]))
         {
          if(CFlag)
          {
             Console.WriteLine("WA");
            break;
          }

          if(s[i] == 'C'&&!CFlag)
          {          
            CFlag = true;
          }

         }
         
       }
           
     }
     
   }
 }