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;

namespace ABC104
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            string subs = "";
            string ans = "AC";
            int flag = 0;
            if (s.Substring(0, 1) != "A") { ans = "WA"; }
            if (s.Substring(1, 1) == "C" || s.Substring(1, 1) == "A") { ans = "WA"; }
            for (int i = 2; i < s.Length-1; i++)
            {
                subs = s.Substring(i, 1);
                if (subs == "C" && flag == 1) { ans = "WA"; }
                if (subs == "C") { flag = 1; }

            }
            if (flag == 0) { ans = "WA"; }
            if(s.Substring(s.Length-1)=="A"|| s.Substring(s.Length - 1) == "C") { ans = "WA"; }
            Console.WriteLine(ans);
        }
    }
}