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 <iostream>
#include <string>
#include <cctype>
std::string s;

int main(){
  
  std::cin >> s;
  
  std::string ans = "AC";
  int len = s.size();
  std::string sub = s.substr(2, len-3);
  int low=0;
  
  int f = s.find('C');
  int b = s.rfind('C');
  if(f != b) ans = "WA";
  if(f <2 or len-3 < f) ans = "WA";
  if(s.front() != 'A') ans = "WA";
  for(int i=0; i<len ;i++){
    if(islower(s[i])) low++;
       }
  if(low != (len-2)) ans = "WA";
       
  std::cout << ans << '\n';

}