Auto populate cell from a repeated number

I need help finding a way to auto populate cells that have repeated numbers into new cells. Here's what I mean:
On cells A1 thru A10 I have the followig numbers (1,2,3,4,5,1,2,3,1,3) where the number 1 and 3 repeat twice after the firts time, the number 2 repeats once after the first time. Therefore I would like auto populate cells B1 and C1 with the number 1 (because it appears twice after the fisrt time) and cell B2 with the number 2 (because it repeats once) and cells B3 and C2 with the number 3 (because it repeats twice).
Please try to avoid macros if possible. I don't know how to use them yet. Unless the macro comes with step by step instructions. Thank you for your help and time.