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 Lua (5.3.2) (judge verdict: Accepted)


function isLower(c)
	return string.lower(c) == c
end
function solve(s)
	if string.sub(s, 1, 1) ~= "A" then
		return false
	end
	if not isLower(string.sub(s, 2, 2)) or not isLower(string.sub(s, #s, #s)) then
		return false
	end
	local num = 0
	for i = 3, #s - 1 do
		local c = string.sub(s, i, i)
		if not isLower(c) then
			if num == 0 and c == "C" then
				num = 1
			else
				return false
			end
		end
	end
	if num == 0 then
		return false
	end
	return true
end
local s = io.read()
if solve(s) then
	print("AC")
else
	print("WA")
end