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: Accepted)

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

typedef long long ll;

int max(int a, int b){
  if(a > b) return a;
  else return b;
}
int min(int a, int b){
  if(a < b) return a;
  else return b;
}

int sort(const void *a ,const void *b){
  return *(int*)a - *(int*)b;
}

int main(){

  char s[11];
  scanf("%s",s);
  int len = strlen(s);

  /*小文字判定*/
  for(int i = 0; i < len; ++i){
    if(s[i] != 'A' && s[i] != 'C'){
      if(s[i] - 'a' < 0){
        printf("WA");
        return 0;
      }
    }
  }

  /*C文字判定*/
  int C_judge = 0;
  for(int i = 2; i < len-1; ++i){
    if(C_judge == 1 && s[i] =='C'){
      printf("WA");
      return 0;
    }
    if(s[i] == 'C') C_judge = 1;
  }

  if(s[0] == 'A' && C_judge == 1){
    printf("AC");
  }else{
    printf("WA");
  }

  return 0;
}