There are total of 18 topological orderings possible.
Out of which only 2 does not satisfy both the constraints .
1$\rightarrow$ 2$\rightarrow$4$\rightarrow$5$\rightarrow$6$\rightarrow$8$\rightarrow$7$\rightarrow$9$\rightarrow$10
1->2->4->5->6->8->9->7->10
If the question is which follows both 1 and 2,then answer is $5$.
If the question is only about either 1 or 2 ,then also answer is $16$