I got in Column A

A0
A0
A0
A0
B2
B2
B2
B3
B3
B4
B5
B5
B6
B7
B7
C0
C0
C0
C1
C2
C2
...
...
...

I need write formula in Column C1 which will SKIP duplicates
A0
B2
B3
B4
B5
B6
B7
C0
C1
C2

Plz help Thanks