main=getChar>>=mapM putStrLn.f
f '['=w"A B C"!w"ABC DEF"
f 'A'=w"A"!["","B"]!("":w"ABC DEF")!w"FF"!("":w"X Y Z")
f _=("":w"Objective- Aspect Concept")!w"C D"!("":w"++ -- # omega")
a!b=[x++y|x<-a,y<-b]
w=words