lock cells when input data into certain cells

Hello, I am new on this forum and would really appreciate your answers to my request:
How to lock cells when any data is input into any cell, I explain with an example:
into cells A1 to A2, I can input data, but if any data is input cells from A3 to A10 are locked (I have no problem with this one)
the problem comes that into the same cells, I should also be able to input data into cells from A3 to A10, so then A1 to A2 are locked.
Hope my request is clear enough to know how to meet both conditions into the same column.
Thank you so much for your help!