Entering Cell Contains - Blank/Not Blank logic

[LMaeExcel]

I would really appreciate some help!! I am trying to figure out how I can accomplish the following logic:

I have files that are assigned to one person, and can switch assignments. I need to locate these switches for specific people.

My sheet will look something like what is shown below. The logic needed for my "Assignment (person)" column, will behave by always entering the name in "2nd person", unless blank, and if blank, it will enter the contents in "1st Person".

I have been working on this for hours! Any guidance would be so much appreciated!

[TABLE="class: grid, width: 500, align: center"]
<tbody>[TR]
[TD]1st Person
[/TD]
[TD]2nd Person
[/TD]
[TD]Assignment (person)
[/TD]
[/TR]
[TR]
[TD]Jerry
[/TD]
[TD]Angie
[/TD]
[TD](formula will go in this column)
[/TD]
[/TR]
[TR]
[TD]Angie
[/TD]
[TD]Barbara
[/TD]
[TD]Barbara
[/TD]
[/TR]
[TR]
[TD]Joe
[/TD]
[TD][/TD]
[TD]Joe
[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]Randal
[/TD]
[TD]Randal
[/TD]
[/TR]
[TR]
[TD]Jerry
[/TD]
[TD][/TD]
[TD]Jerry
[/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Sarah
[/TD]
[TD][/TD]
[TD]Sara
[/TD]
[/TR]
</tbody>[/TABLE]

 

[Joe4]

Let's say that the first cell your formula is to go in is in cell C2.
Then your formula would look like this:

=IF(B2<>"",B2,A2)