I'm working on a schedule that needs to count N or D and assign it a value of
12

the chart i'm working with looks something like this

sun mon tues wed thurs fri sat
mary vac vac vac vac vac va d va-n
tyler off off n n d d off
john d d d d off off d
joe n n off off n n n


what function can i use to count how many times a person works "n" or "va d"
or "va-n" or "d" and assign a value of 12 for each of those characters but a
value of ZERO for off or vac?