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::stdin;

fn beginning_with_capital_a(input: &str) -> bool {
    input.chars().next().unwrap() == 'A'
}

fn intermediate_capital_c(input: &str) -> bool {
    input[2..input.len()-1].chars().any(|c| c == 'C')
}

fn exactly_two_capitals(input: &str) -> bool {
    input.chars().map(|c| c.is_uppercase() as i32).fold(0 as i32, |x, y| x + y) == 2
}

fn main () {
    let mut buf = String::new();
    stdin().read_line(&mut buf).unwrap();
    let input = buf.trim_right();

    let condition = beginning_with_capital_a(input) && intermediate_capital_c(input) && exactly_two_capitals(input);
    let ans = if condition { "AC" } else { "WA" };
    println!("{}", ans);
}