The maximum number of sets obtainable from A and B applying union and difference operation is
A∪B,A−B,B−A(A∪B)−(A−B)=B(A∪B)−(B−A)=AAΔB=(A−B)∪(B−A) and (A∪B)−(AΔB)=A∩B(A−B)−A=ϕ
Thus, the required number is 8.