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++ (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
using namespace std;
int main() {
    string s;
    cin >> s;
    //cout << s << endl;
    if (s[0] != 'A') {
        //cout << "1" << endl;
        cout << "WA" << endl;
        return 0;
    } else {
        int cnt = 0;
        int j;
        for (int i = 1; i < s.length(); i++) {
            if (i >= 2 && i <= (s.length() - 1) - 1 && s[i] == 'C') { //front 3, end 2
                cnt++;
                j = i;
            }
            //cout << "i " << i << " cnt " << cnt << endl;
            if ((s[i] < 'a' || s[i] > 'z') && i != j) {
                //cout << "2" << endl;
                cout << "WA" << endl;
                return 0;
            }
        }
        if (cnt == 1) {
            cout << "AC" << endl;
        } else {
            cout << "WA" << endl;
        }
    }
}