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 (1.42.0) (judge verdict: Accepted)

#![allow(unused_imports)]

use text_io::*;
use proconio::*;
use std::collections::*;
use std::process::exit;
use std::cmp::*;
use itertools::Itertools;

fn main() {
    let a: String = read!();
    let v = a.chars().collect_vec();
    let mut b:usize=0;
    for i in 0..v.len() {
        if i==0 {
            if v[i]=='A' {
                b+=1;
            }
        }
        else {
            if v[i]=='C' {
                if i==1 || i==v.len()-1{
                    println!("WA");
                    exit(0);
                }
                b+=2;
            }
            else if v[i]==v[i].to_ascii_uppercase() {
                println!("WA");
                exit(0);
            }
        }
    }
    if b==3 {
        println!("AC");
    }
    else {
        println!("WA")
    }
}