marlin setup to ardiuno uno board

I have uno r3 board, cnc shield v3 and A4988 driver. I can not compile and compile marlin setup. The board is compiled when you choose the mega 2560 but it is not compiled when you choose your own board. It gives an error when selecting moother board. Which mother board should I choose?
I will be glad if you help me. thanks in advance

Probably can't be done. Marlin is very complex and likely will not fit in the memory of the Uno. Save yourself a lot of headaches by just buying a Mega.

I second what Pert said, there is no way that Marlin will work on an Uno. Grbl will, though.