Question: Which landlocked country diplomatically related to Serbia has the lowest minimum age for compulsory education ?
Paraphrase: Which landlocked country that is diplomatically associated with Serbia has the lowest minimum age for mandatory education?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q123480 . ?ent wdt:P3270 ?obj . ?ent wdt:P530 wd:Q403. } ORDER BY ASC(?obj)LIMIT 5 
Answer: Hungary, Zimbabwe