Subtract a constant from a measure

[MarcoT]

I'm trying to create a measure on DAX that have to subtract 2 measures from a constant (that is 14). The problem is that when I calculate it it duplicates the results row. Here's the formula:

Missed flows = (14 - CALCULATE( DMSFact'[# Not Available] ) )-'DMSFact'[Dealer_TOT_Y]

where 

# Not Available and Dealer_TOT_Y are two count measure:

Dealer_TOT_Y =
CALCULATE(COUNT('DMSFact'[Dealer Int])
,'DMSFact'[Dealer Int]="Y"
,GROUPBY('DMSFact','DMSFact'[Dealer Code]))

# Not Available =
CALCULATE(COUNT('DMSFact'[Flag NotAvailable])
,'DMSFact'[Flag NotAvailable]="Y"
)

The result I want to display is the Missed flows for each dealer, in such a form:

Insted I get this:

[tamerj1 · Accepted solution]

Hi @MarcoT 
Please use

Missed flows =
VAR NotAvilable = [# Not Available]
VAR Dealer = [Dealer_TOT_Y]
RETURN
    IF (
        NOT ISBLANK ( NotAvilable ) || NOT ISBLANK ( Dealer ),
        14 - NotAvilable - Dealer
    )