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)

var lines = [];

var readline = require('readline');
var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
})

rl.on('line', function (x) {
    lines.push(x);
});

rl.on("close", function () {
    var S = lines[0].split("");
    if (S[0] !== "A") { console.log("WA"); return (0); }
    if (S[1] !== S[1].toLowerCase()) { console.log("WA"); return (0) }

    var counter = 0;
    for (var i = 2; i < S.length - 1; i++) {

        if (S[i] === "C") { counter++; S[i] = "c"; }
        if (1 < counter) { console.log("WA"); return (0); }
        if (S[i] !== S[i].toLowerCase()) { console.log("WA"); return (0); }

    }
    if (counter === 0) {console.log("WA"); return (0) }
    if (S[S.length - 1] !== S[S.length - 1].toLowerCase()) { console.log("WA"); return (0) }

    console.log("AC");
});