Graphs and Degrees · Medium problem

Graph $F$ has a hub vertex $0$ joined to six others, $1,\ldots,6$, and three extra edges $12$, $34$, $56$ among them (so $0$ together with each pair $\{1,2\}$, $\{3,4\}$, $\{5,6\}$ forms a triangle, and there are no other edges). How many triangles does $F$ contain?