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

char s[20];
int n;
int main() {
    scanf("%s", s + 1);
    int flag = 1;
    
    int n = strlen(s + 1), cnt = 0;
    flag = s[1] == 'A';
    // [3, n - 2]
    cnt = 0;
    for(int i = 3 ; i <= n - 1 ; ++ i) if(s[i] == 'C') ++ cnt;
    if(cnt != 1) flag = 0;
    
    cnt = 0;
    for(int i = 1 ; i <= n ; ++ i) if(!('a' <= s[i] && s[i] <= 'z') || (s[i] != 'A' && s[i] != 'C')) ++ cnt;
    if(cnt) flag = 0;
    
    
    if(flag) puts("AC");
    else puts("WA");
}