A heat engine with $0\mathrm{.}100$ molmol of a monatomic ideal gas initially fills a $2000$ cm$3$cm$3$ cylinder at $600$ KK$.$ The gas goes through the following closed cycle:

$-$ Isothermal expansion to $6000$ cm$3$cm$3.$

$-$ Isochoric cooling to $400$ KK$.$

$-$ Isothermal compression to $2000$ cm$3$cm$3.$

$-$ Isochoric heating to $600$ KK$.$ How much work does this engine do per cycle?

Express your answer with the appropriate units. What is its thermal efficiency?

Express your answer as a percentage.