Which is the piano cycle with the lowest number of parts of a work of art, whose parts of the class is variation?
select ?ent where { ?ent wdt:P31 wd:Q1746056 . ?ent wdt:P2635 ?obj . ?ent wdt:P2670 wd:Q214981. } ORDER BY ASC(?obj)LIMIT 5 
piano cycle: Q1746056 theme and variations: Q214981