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 Rust (1.15.1) (judge verdict: Accepted)

use std::io;

fn main() {
	let mut buf = String::new();
	io::stdin().read_line(&mut buf).expect("");
	let s:Vec<char> = buf.trim().chars().collect();
	let mut flag = false;
	let mut cnt = 0;
	let mut c = 0;
	/*for i in 0..s.len() {
		println!("{}", (s[i] as i16) - ('A' as i16));
	}*/
	if s[0] == 'A' {
		//if s.len() != 4 {
			for i in 2..(s.len() - 1) {
				if s[i] == 'C' {
					cnt += 1;
					c = i;
				}
				if cnt > 1 {
					break;
				}
			}
			if cnt == 1 {
				for i in 1..s.len() {
					if (s[i] as i32) - ('A' as i32) <= 25 && c != i {
							break;
					}
					if i == s.len() - 1 {
						flag = true;
					}
				}
			}
		//}
	}
	if flag {
		println!("AC");
	}else{
		println!("WA");
	}
}