GIF frames deleting script.

[rey]

I understand it's not polite to bluntly ask for anybody to make a script that i need, so hope asomebody can give hints on commands i must use to try to achieve my goal.

The goal is a a script that makes automatic deletion of GIF frames(layers) based on 2 parameters, and then exports file in original location adding some "copy"/"-01" to name. The deletion logic should work like "delete X frames after each Y frames".
For example:
 = GIF with 22 frames, parameters are X=2 Y=3, after processing there will be: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
 = GIF with 22 frames, parameters are X=1 Y=4, after processing there will be: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
[crossed frames are deleted]

Hope for your help.