give unique Values to set of data if rows are continues

[aravindhan_31]

Hi
I have some values in Sheet1 Colmn A like this.
Col A
A
A
A
B
B
C
A
B
A
I need to give a unique set of values for the rows which are continues
Col A Result
A 1
A 1
A 1
B 1
B 1
C 1
A 2
B 2
A 3

with the above example, first 3 values are continues so i give 1 for those, the next a appears after some other values so I assign 2 again A appears after some rows of data o I assign 3, similarly the same thing to be done for all the values in Column A
Is this possible in formulas or a macro

I have attached the sample file



Appreciate your help