IF statements with dates and criteria

Hello,
I needs assistance with "If "statements and criteria within the statement .

Column A has a set of start dates
Column B has a set of End dates
Column C has the If statements with criteria resulting in a date.

So here is what I'm trying to create:
IF A= B then the result in C is the B date, but if A is not = B, then result in C is B date +14 more days.

I have read many examples and can seem to be able to put all of this into one If statement.

Any help is greatly appreciated.

Thank you.