Alternative to using multiple nested IF statements

I have a spreadsheet set up as follows:

Col A........Col B......Col C........Col D.....Col E.........Col F......Col G........Col H
Student....Grade....Student.....Grade....Student.....Grade....Student.....Grade....
Mike..........Pass......Tim..........Pass.......Joe............Fail.........Sue.........Pass
Mike..........Pass......Tim..........Pass
Mike..........Pass......Tim..........Fail
Mike..........Pass......Tim..........Pass.......Joe............Pass........Sue.........Pass

For each line in file, I need to determine if all students have passed the course. If all students have passed then I need to make a notation in another cell which indicates "OK". If one or more students have failed, then I need to make a notation of "Review". For example:

Line 1 = Review
Line 2 = Ok
Line 3 = Review
Line 4 = Ok

I am trying to avoid having to write some lengthy nested if statement to solve. In some cases, I may have as many as 20 students in one line and just not sure how to test if all have passed or at least one has failed. Thanks in advance for any comments.