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>

#define ld long double
#define ll long long int
#define ull unsigned long long int
#define vi vector<int>
#define vl vector<ll>
#define vvi vector< vector<int> >
#define vvl vector< vector<ll> >

using namespace std;

int main() {

    string S;
    cin >> S;

    string ans;

    /**
     * 以下の３つの条件を満たすか
     */
    bool doseBeginA = false;
    bool doesIncludeC = false;
    bool isSmallLetter = true;

    // 1個目
    if (S[0] == 'A') {
        doseBeginA = true;
    }

    // 2,3個目
    for (int i = 1; i < S.length(); ++i) {
        char temp = S[i];
        if (temp == 'C' && i > 1 && i != S.length() - 1) {
            doesIncludeC = true;
        } else if (isupper(temp)) {
            isSmallLetter = false;
        }

    }

    ans = "WA";
    if (doesIncludeC && doseBeginA && isSmallLetter) {
        ans = "AC";
    }

    cout << ans << endl;

    return 0;
}