How to Unhide column A in Excel and Google Doc?

Let's say I hide column A in excel or in google doc, how can I unhide it (show column A again). Column A is the most left column. I have column B,C and D etc...

In Excel, if a column is hidden, the separator line between the column headers is a bit more pronounced, i.e. thicker. To unhide column A, hover over the dark line next to the column B header, right-click an select "Unhide".

Well, on Google Docs you have little > mark to click on and expand hidden colums.
On LibreOffice you can click on the first header to mark all columns and rows and than click on Format/Row(Column)/Show.
I personally don't use excel so I'm guessing it's same as this second example