Returning Column Headers for Max Values with Ties

Hello, first thread here. If more information is needed, please let me know.

I would like to pull the highest month of sales in a particular row, which I believe I can manage. The kicker is that some months match others. In this case, I would like to pull all the months that match the highest value (in adjacent cells). I was using an INDEX function with a LARGE function within it, but when there are ties, it pulls the same month's column header twice.

Can someone please take a look and let me know if there is a "simple" way to do this?

Thank you!