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 <bits/stdc++.h>
using namespace std;

int main()
{
    string S = "AtCoder";
    //cin >> S;
    if (S[0] != 'A')
    {
        cout << "WA";
        return 0;
    }
    bool flag = false;
    for (int i = 1; i < S.size(); i++)
    {
        if (isupper(S[i]))
        {
            if (i >= 2 && S.size() - 2 > i)
            {
                if (S[i] == 'C')
                {
                    if (flag)
                    {
                        cout << "WA";
                        return 0;
                    }
                    flag = true;
                }
                else
                {
                    cout << "WA";
                    return 0;
                }
            }
            else
            {
                cout << "WA";
                return 0;
            }
        }
    }

    cout << "AC";
}