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 static System.Console;

class Program {
	static void Main() {
		var S = ReadLine();
		WriteLine(Judge(S) ? "AC" : "WA");
	}
	static bool Judge(string S) {
		var i = 0;
		var flg = false;
		foreach (var c in S) {
			if (i == 0) {
				if (S[0] != 'A') {
					return false;
				}
			} else if (2 <= i && i < S.Length - 1) {
				if (S[i].ToString().ToUpper() == S[i] + "") {
					if (flg) {
						return false;
					}
					flg = true;
				}
			}
			i++;
		}
		return flg ? true : false;
	}
}