i wanna know how to find those cell in a worksheet which are same for example

question
columnA columnB
1 9
3 2
2 8
4 7
5 6
6 5
7 4

need answer in following condition

AA)
following are maching with others
columA columnB
2 2
4 4
5 5
6 6
7 7

BB)
and these are no mach or diffrent with others
1 8
3 9

hope every think is clear if you need further please feel free to ask
basicaly it is my big problem i m losting my lot of time bcz of this manual
serching... Malik Nadeem