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.Runtime.Remoting.Contexts;

namespace Contest
{

    class Scanner
    {
        private string[] line = new string[0];
        private int index = 0;
        public string Next()
        {
            if (line.Length <= index)
            {
                line = Console.ReadLine().Split(' ');
                index = 0;
            }
            var res = line[index];
            index++;
            return res;
        }
        public int NextInt()
        {
            return int.Parse(Next());
        }
        public long NextLong()
        {
            return long.Parse(Next());
        }
        public string[] Array()
        {
            line = Console.ReadLine().Split(' ');
            index = line.Length;
            return line;
        }
        public int[] IntArray()
        {
            var array = Array();
            var result = new int[array.Length];
            for (int i = 0; i < array.Length; i++)
            {
                result[i] = int.Parse(array[i]);
            }

            return result;
        }
        public long[] LongArray()
        {
            var array = Array();
            var result = new long[array.Length];
            for (int i = 0; i < array.Length; i++)
            {
                result[i] = long.Parse(array[i]);
            }

            return result;
        }
    }

    class Program
    {
        private string S;
        private void Scan()
        {
            Scanner sc = new Scanner();
            S = sc.Next();
        }


        public void Solve()
        {
            Scan();
            bool flagA = false;
            int cntC = 0;
            for (int i = 0; i < S.Length; i++)
            {
                if ('A' <= S[i] && S[i] <= 'Z')
                {
                    if (i == 0 && S[i] == 'A')
                    {
                        flagA = true;
                    }

                    if (2 <= i && i <= S.Length - 2 && S[i] == 'C')
                    {
                        cntC++;
                    }
                }
                else if ('a' <= S[i] && S[i] <= 'z')
                {

                }
                else
                {
                    Console.WriteLine("WA");
                    return;
                }
            }

            if (flagA && cntC == 1)
            {
                Console.WriteLine("AC");
            }
            else
            {
                Console.WriteLine("WA");
            }
        }

        static void Main() => new Program().Solve();
    }
}