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: Accepted)

'use strict'

function main(input) {

    input = input.split("\n")
    input = input[0].split('')

    let ans = "AC"


    //found A
    if (input[0] != "A") {
        ans = "WA"
    }

    //found C
    //S の先頭から 3 文字目と末尾から 2 文字目の間（両端含む）
    let c = false
    let ci = 0
    for (let i = 2; i < input.length - 1; i++) {
        if (input[i] == "C" && !c) {
            c = true
            ci = i
        } else if (input[i] == "C" && c) {
            c = false //すでにCが見つかり、さらに　Cが見つかったら false
        }
    }
    if (!c) ans = "WA"


    // is lowercase
    let tmp = input;
    tmp[0] = 'a' // A 削除
    if (ci != 0) tmp[ci] = 'c' // C 削除

    tmp = tmp.join('')
    let boo
    boo = tmp.match(/^[a-z]+$/) ? true : false
    if (!boo) ans = 'WA'

    //judge
    console.log(ans)

}

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