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 Perl (v5.18.2) (judge verdict: Runtime Error)

@s = ("", split(//, <>));

$r = "AC";
$cnt = 0;
for $i (1 .. $#s){

	if($i == 1){
		if($s[$i] ne 'A'){
			$r = "WA";
			last;
		}
	}elsif(($i >= 3) and (($i <= $#s - 2))){
		if($s[$i] eq 'C'){
			if($cnt == 1){
				$r = "WA";
				last;
			}else{
				$cnt = 1;
			}
		}
		if($s[$i] !~ /[a-z]/i){
			$r = "WA";
			last;
		}
	}else{
		if($s[$i]) eq 'C'){
			$r = "WA";
			last;
		}
		if($s[$i] !~ /[a-z]/i){
			$r = "WA";
			last;
		}
	}
}
$r = "WA" if($cnt == 0);

print "$r\n";