Eliminating duplicate numbers via Mac Excel

I imagine you guys have answer this question a zillion times - SORRY I can't seem to find any reference on this.

Original list:

A1: 8
A2: 7
A3: 1
A4: 0
A5: 6
A6: 6

What I'm wanting is to eliminate is any duplicate numbers (6 on this example):

C1: 8
C2: 7
C3: 1
C4: 0
C5: 6
C6: -

in b1 filled down
=IF(A1="","",IF(COUNTIF($A$1:A1,A1)=1,ROW(),""))
in c1 filled down
=IF(ROW(A1)>COUNT($B$1:$B$200),"",INDEX($A$1:$A$20,MATCH(SMALL($B$1:$B$200,ROW(A1)),$B$1:$B$200,0)))