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: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <ctype.h>

int main(void) {
  char s[12];
  int len, count = 0;

  if(scanf("%s", s) == 1);

  len = strlen(s);

  if(s[0] == 'A' && islower(s[1]) && islower(s[len-1])) {
    for(int i = 2; i < len; i++) {
      if(i == len - 1) {
        if(isupper(s[i])) {
          printf("WA");
          return 0;
        }
      } else if(s[i] == 'C') {
        if(count == 1) {
          printf("WA");
          return 0;
        }
        count++;
      } else if(isupper(s[i])) {
        printf("WA");
        return 0;
      }
    }
  } else {
    printf("WA");
    return 0;
  }

  if(count == 0) {
    printf("WA");
    return 0;
  }

  printf("AC");

  return 0;
}