Half is the opposite of Birthday. Birthday is related to Song. Song is related to Perfect. Perfect is similar to Exact. 
International is related to Ambassador. Ambassador is related to Representative. Representative is related to Elect. Elect is related to Voter. 
Half <--Antonym--> Birthday <--RelatedTo--> Song <--RelatedTo--> Perfect <--SimilarTo--> Exact 
International <--RelatedTo--> Ambassador <--RelatedTo--> Representative <--RelatedTo--> Elect <--RelatedTo--> Voter 