Diazepam, marketed as an antianxiety medication under the name Valium, has three rings, eight double bonds, and the formula $\mathrm{C}_{16} \mathrm{H}_{7} \mathrm{CiN}_{2} \mathrm{O}$. How many hydrogens does diazepam have? (Calculate the answer, don't count hydrogens in the structure.)