How to add an calculated column to give the number of unique values in a row

[SC Chou]

reference column

Col1

Col2

Col3

Calculated Column

 

 

r1

c11

c21

c31

number of unique values in (c11,c21,c31)

 

 

r2

c12

c22

c32

number of unique values in (c12,c22,c32)

 

 

r3

c13

c23

c33

number of unique values in (c13,c23,c33)

 

 

 

 

As title, I have a data table shown above.

 

Here I want to get the number of unique values in (col1,col2,col3)in each row

Does anyone know how to attain this goal by using custom expression

 

Many thanks!