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: Accepted)

#include<iostream>
#include<string>

using namespace std;

int main() {
	string s;
	cin >> s;
	int len = (int)s.size();

	if (s[0] == 'A') {
		s[0] = 'a';
		int a;
		for (a = 2; a < len - 1; a++) {
			if (s[a] == 'C') {
				s[a] = 'c';
				break;
			}
		}
		if (a == len - 1) {
			cout << "WA";
		}
		else {
			string ss = s;
			for (int b = 0; b < len; b++) ss[b] = tolower(ss[b]);
			if (ss != s)cout << "WA";
			else cout << "AC";
		}
	}
	else cout << "WA";

	cout << endl;

	return 0;
}