New month, new code golf!

You will receive a string with a label code with numbers and letters. Our challenge is to check if this code begins with 1, 2, or 3 and ends with A, B, C, S, or R. It should return true(1) if so or return false(0) otherwise. As usual shortest solution wins.

##Input "198739A79D9R"

##Output 1

##Note

• The string only contains numbers and upper-case letters. No other special characters.
• Use this code to check the solution length
• You also can use this test case here

Rules

1. The signature of the contest entry MUST be:

Class codeGolf.LabelCode
{

ClassMethod Validate(s As %String) As %Boolean
{
}

}

2. It is forbidden to modify class/signature, including but not limited to:

• Adding inheritance
• Setting default argument values
• Adding class elements (Parameters, Methods, Includes, etc).

3. It is forbidden to refer to non-system code from your entry. For example, this is not a valid entry:

ClassMethod Validate(s) As %Boolean 
{
  q ##class(myPackage.myClass).test(s)
}

4. The use of $ZWPACK and $ZWBPACK is also discouraged.

My best attempt so far is 30 characters. What's yours?