Count if equal to first non error cell

Hi I tried to post this once so apologies if this is second post...

I want to count the number of times 3 or -3 occurs in range A8:A15 depending
on whether 3 or -3 comes first. If 3 is A8 then count how many times 3
occurs in the range. If A8 and A9 equal #n/a and A10 equals -3 then count
how many times -3 is in the range (there many be 2 -3's and one occurance of
a postive 3 for example)

Thanks