How to count unique values in four columns horizontal array

Hi Forum,

I hope you can help me with this question.

I have an Excel file with four columns where I need to count the unique value row by row (I guess it's 'Horizontal array' or row by row).

Example 1:
Cell A2: Value 1
Cell B2: Value 26
Cell C2: Value 33
Cell D2: Value -1
=> In this example, the result is four unique values.

Example 2:
Cell A2: Value 1
Cell B2: Value 26
Cell C2: Value 1
Cell D2: Value -1
=> In this example, the result is three unique values.

Example 3:
Cell A2: Value 1
Cell B2: Value 1
Cell C2: Value 1
Cell D2: Value 1
In this example, the result is one unique value.

Thanks in advance for your help.

Kind regards,
Arne