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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

// Todo
// * [x] sを分解する関数
// * [x] sから"AC"か"WA"を返す関数

function parse(s) {
  const lastIndex = s.length - 1

  return [
    s.substring(0, 2), // "ABCDE"から"AB"を取り出す
    s.substring(2, lastIndex), // "ABCDE"から"CD"を取り出す
    s.substring(lastIndex), // "ABCDE"から"E"を取り出す
  ]
}

function f(s) {
  const arr = parse(s)

  return arr[0].match(/^A[a-z]*$/) && arr[1].match(/^[a-z]*C[a-z]*$/) && arr[2].match(/^[a-z]*$/) ? "AC" : "WA"
}

module.exports = {
  parse,
  f,
}

function Main(input) {
  console.log(f(input))
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"))