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 (Clang 3.8.0) (judge verdict: Accepted)

#include <algorithm>
#include <iostream>
#include <string>
#include <utility>
#include <vector>
#define FOR(i, a, b) for (int i = a, i##_len = (b); i < i##_len; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) (x).begin(), (x).end()
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());
#define EPS (1e-7)
#define INF (1e9)

using namespace std;

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);

  string s;
  cin >> s;

  const char *str = s.c_str();
  int len = s.length();
  if (str[0] != 'A')
  {
    cout << "WA" << endl;
    return 0;
  }

  int C = 0;
  int lower = 0;
  FOR(i, 1, len)
  {
    // cout << i << str[i] << endl;
    if (islower(str[i]))
    {
      lower++;
    }
    else if (2 <= i && i <= len - 2 && str[i] == 'C')
    {
      C++;
    }
  }

  // cout << C << " " << lower << endl;

  if (C == 1 && lower == len - 2)
  {
    cout << "AC" << endl;
  }
  else
  {
    cout << "WA" << endl;
  }
}