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

int main()
{
  string s;
  bool C_flag = false, flag = true;

  cin >> s;
  for (int i = 0; i < s.size(); i++)
  {
    if (i == 0)
    {
      if (s[i] != 'A')
        flag = false;
    }
    else if (s[i] == 'C')
    {
      if (!C_flag && 1 < i && i < s.size() - 1)
        C_flag = true;
      else
        flag = false;
    }
    else if (s[i] < 'a' || 'z' < s[i])
      flag = false;
    if (!flag)
      break;
  }
  cout << (flag && C_flag ? "AC" : "WA") << endl;
}