Removing letters only at the end of a cell

Hey all. I'm hoping someone can help me figure this out, as I have only a mediocre understanding of the tools Excel offers me, and I've been stressing out over this for an hour. Any help would be greatly greatly appreciated.

I have a column, and I need to get only the letters at the end out. As such:

A1
djf-2821ab
djf-2820qbx
djz-2820ybsdc
doa-202a1
dob-1018

What can I do to remove only "ab", "qbx" and "ybsdc" from the end of these cells?

Thanks much.