Numbering/ Marking Steel Member

Dear all I am beginner with dynamo I am looking for easiest way or nodes to define my script so I need some guidance

I have project with large number of beam and coulmn How to mark or number steel beams or column based on the different cutting length for example I want column with cut length 3 m to be C1 and 4 m C2 and beam with cutting length 3 m to be B1 and so on .

It kinda depends on your data, but Dictionaries would be a good start. An IF statement may also work.