Realize each of the following functions as a minimum two-level NAND-gate circuit and as a minimum two-level NOR-gate circuit

Realize each of the following functions as a minimum two-level NAND-gate circuit and as a minimum two-level NOR-gate circuit.

(a) F(A,B,C,D) = BD′ + B′CD + A′BC + A′BC′D + B′D′

(b) f(a,b,c,d)=ΠM(0,1,7,9,10,13)·ΠD(2,6,14,15)