What is the ice giant with the lowest flattening whose described by source is Otto's encyclopedia?
select ?ent where { ?ent wdt:P31 wd:Q1319599 . ?ent wdt:P1102 ?obj . ?ent wdt:P1343 wd:Q2041543} ORDER BY ASC(?obj)LIMIT 5 
ice giant: Q1319599 ottův slovník naučný: Q2041543