Give a regular expression for the language that is produced by the formal grammar that has the starting symbol S$,$ the set of terminals $\{0,1\},$ the nonterminals $\{$S$,$A$,$B$,$C$\},$ and the following production rules: Finni$$ reglulega seg$$ fyrir m$$li$$ sem er framleitt af reglulegu m$$ll$$singunni sem hefur upphafst$$kni$$ S$,$ mengi lokat$$kna $\{0,1\},$ millit$$knin $\{$S$,$A$,$B$,$C$\},$ og eftirfarandi m$$lreglur: S $->0|0$A$,$ and A $->0$A $|1$B $|1$C B $->0$B $|1$A C $->0$