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 Go (1.6) (judge verdict: Accepted)

package main
import . "fmt"
import . "strings"
import . "os"
func main() {
  var s string
  Scan(&s)
  if Count(s,"A") != 1 || Count(s,"C") != 1 {
    Println("WA")
  } else if s[0:1] == "A" && Contains(s[2:len(s)-1],"C") {
    if Contains(s,"B") {
      Println("WA")
    } else {
      for i:=68;i<91;i++ {
        if Contains(s,string(i)) {
          Println("WA")
          Exit(0)
        }
      }
      Println("AC")
    }
  } else {
    Println("WA")
  }
}