<Tr> <Th> Audio format </Th> <Td> Dolby Digital 5.1 </Td> </Tr> <Tr> <Th> Original release </Th> <Td> October 26, 2015 (2015 - 10 - 26)--present (present) </Td> </Tr> <Tr> <Th_colspan="2"> External links </Th> </Tr> <Tr> <Th> Website </Th> <Td> www.cwtv.com/shows/supergirl </Td> </Tr>

Which episode did the flash appear in supergirl