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; cin >> s;
    bool flag = true;
    if(s.at(0) != 'A'){
        flag = false;
    }
    else{
        //3~size()-1文字までに大文字がCのみ
        int cnt = 0;
        for(int i=1;i<s.size();i++){
            if(i == 1 || i == s.size()-1){
                if(isupper(s.at(i))){ //i文字目が大文字
                    flag = false;
                    break;
                }
            }
            else{
                if(isupper(s.at(i))){ //i文字目が大文字
                    if(s.at(i) == 'C'){ //i文字目がC
                        cnt++;
                    }
                    else{
                        flag = false;
                        break;
                    }
                }
            }
        }
        if(cnt != 1){
            flag = false;
        }
    }
  string ans;
    if(flag){
        ans = "AC";
    }
    else{
        ans = "WA";
    }
    
    cout << ans << endl;
}