In 2005 two city council members, Ralph Inzunza and Deputy Mayor Michael Zucchet – who briefly took over as acting mayor when Murphy resigned – were convicted of extortion, wire fraud, and conspiracy to commit wire fraud for taking campaign contributions from a strip club owner and his associates, allegedly in exchange for trying to repeal the city's "no touch" laws at strip clubs. Both subsequently resigned. Inzunza was sentenced to 21 months in prison. In 2009, a judge acquitted Zucchet on seven out of the nine counts against him, and granted his petition for a new trial on the other two charges; the remaining charges were eventually dropped.

Answer this question, if possible (if impossible, reply "unanswerable"): How long was Inzunza's  prison sentence?
21 months