Subtract counts if both condition are met /same Serialnumber

[Applicable88]

Hello,

I have following table:

Serialnumber	Status
1111	B
1111	M
2222	B
2222	M
3333	B
3333	M
5432	B
1234	B

I want to count the serialnumbers with status 'B' . Only in case the serialnumber already exist with status 'M' it should be deducted from the first count.

like that: count({$<Status={B}>}serialnumber)- count({$<Status={M}, (serialnumber of  B= seralnumber of M>}serialnumber) 

Is that better solve with If-Statement? can you give me example in if and in set analysis please. 

I hope I explained my problem well. 

Thank you in advance.

[Applicable88]

sorry @Taoufiq_Zarra  about the format of the additional columns.

But it the website didn't accept my formatted table from excel . 

and no... in qliksense I left the identifier in the fuction, so it cannot be changed through selections. I aware of that. no filter was on anyway. 

[Taoufiq_Zarra · Accepted solution]

@Applicable88  if its the same logic you need:

=sum({<Status={'B'},Serialnumber={"= count({<Status={'M'}>} Status)>0"}>} Value)

and

=sum({<Status={'B'},Serialnumber={"= count({<Status={'M'}>} Status)>0"}>} Value)

if not can you share also the expected output from the attached sample ?