The compound shown has the molecular formula $\mathrm{C}{}_5\mathrm{H}{}_{10}$. How many structural isomers of this formula exist in total, counting both acyclic (alkenes) and cyclic (cycloalkanes) compounds and the compound shown itself, but ignoring stereoisomers? Give an integer.

The compound is 2-methylbut-2-ene (C5H10, degree of unsaturation 1). Acyclic: pent-1-ene, pent-2-ene, 2-methylbut-1-ene, 3-methylbut-1-ene, 2-methylbut-2-ene = 5. Cyclic: cyclopentane, methylcyclobutane, ethylcyclopropane, 1,1-dimethylcyclopropane, 1,2-dimethylcyclopropane = 5. Total 10 (checked by enumeration).