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 <stdlib.h>
#include <string.h>
#include <math.h>
 
int main()
{
  int a, b, c, X, Y;
  char s[101]={};
  char s_temp[101]={};
  char t[101]={};
  int len=0;
  int N, M;
  int A[20000]={};
  int B[20000]={};
  int C[20000]={};
  int i,j,k;
  int flag=0;
  int tmp=0;
  int min=101;
  int cnt=0;
  int max=0;
  int ans=0;

//  long cnt =0;
  long long A_temp;
//    int k=0;

  scanf("%s", s);
// printf("%d\n", a);

  for(i=0;i<strlen(s);i++){
    if(i==0){
      if(s[i] != 'A'){
        printf("WA\n");
        return 0;
      }
      else{
        flag==1;
      }
    } else {
      if(s[i] == 'C' && flag==1){
        printf("WA\n");
        return 0;
      }
      else if(s[i] == 'C' && flag==0 ){
        flag=1;
      }
      else if((s[i] < 'a') || (s[i] > 'z')){
        printf("WA\n");
        return 0;
      }
    }
    if(i==(strlen(s)-2)) flag=1;
    else if(i==0) flag=1;
    else if(i==1) flag=0;
  }
  
  printf("AC\n");  
  
return 0;
}