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++ (GCC 9.2.1) (judge verdict: Wrong Answer)

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<utility>
#include<tuple>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>

using namespace std;

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

#define BIL ((ll)1e9)
#define MOD ((ll)1e9+7)
#define INF (1LL<<60)           //1LL<<63でオーバーフロー
#define inf (1<<29)             //1<<29でオーバーフロー

int main(int argc,char* argv[]){
    string s;
    cin >> s;

    bool ans=true,ccheck=false;
    for(int i=0;i<s.size();i++){
        if(i==0 && s[i]!='A'){
            ans=false;
            break;
        }else if(i>=2 && i<=s.size()-2 && s[i]=='C'){
            if(ccheck){
                ans = false;
                break;
            }else{
                ccheck=true;
            }
        }else{
            if(s[i]-'a'<0 && s[i]-'a'>25){
                ans=false;
                break;
            }
        }
    }

    if(ans && ccheck)cout << "AC" << endl;
    else cout << "WA" << endl;

    return 0;
}