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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <string>

int main()
{
	std::string S;
	std::cin >> S;
	auto result = "WA";
	if (S[0] == 'A') {
		int C = 0;
		bool b = true;
		int n = static_cast<int>(S.length());
		for (int i = 1; i < n; ++i) {
			if (2 <= i && i < n - 2 && S[i] == 'C') {
				C++;
			}
			else {
				b &= 'a' <= S[i] && S[i] <= 'z';
			}
		}
		if (C == 1 && b) {
			result = "AC";
		}
	}
	std::cout << result << std::endl;
	return 0;
}