How many parameters are needed to describe this distribution?

Consider a distribution consisting of three binary variables which admit the factorisation: $p(a,b,c)=p(a\mid b)p(b\mid c)p(c)$

How many parameters are needed to specify distributions of this form?

Note that this is different to the general case where all variables might be dependent: $p(a,b,c)=p(a\mid b,c)p(b\mid c)p(c)$