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 <string.h>

int isUpper(char c){
  return c < 97 || 122 < c;
}

int main(void)
{
  char S[11];
  scanf("%s", S);
  int state = 0;
  const int len = strlen(S);
  if(S[0] != 'A' || isUpper(S[1]) || isUpper(S[len-1]))
    state = 0;
  else{    
    int c = 0;
    for(int i = 2; i < len-1; i++){
      if(S[i] == 'C'){
        if(c){
          state = 0;
          break;
        } else {
          c++;
          state = 1;
        }
      } else {
        if(isUpper(S[i])){
          state = 0;
          break;
        }
      }

    }
  }
  printf("%s\n", state ? "AC" : "WA");
  return 0;
}