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 5.4.1) (judge verdict: Wrong Answer)

# include <stdio.h>
# include <string.h>

int main(){
    char S[10];
    int flg = 0;

    scanf("%s", S);

    if (S[0] != 'A'){
        flg = 1;
        S[0] = 'a';
    }

    int ct = 0;
    for (int i = 2; i < strlen(S)-1; ++i){
        if (S[i] == 'C'){
            S[i] = 'c';
            ct++;
        }
    }
    if (ct != 1) flg = 1;

    if (flg == 1){
        for (int i = 0; i < strlen(S); ++i){
            if ('a' <= S[i] && S[i] <= 'z')
                continue;
            else{
                flg = 1;
                break;
            }
        }
    }

    if (flg == 0) printf("AC");
    else printf("WA");

    return 0;
}