North-East is not counted. 41 and 49 cannot also because they
are now in TT.
East is Bedok, Tampines and Pasir Ris. Airport terminal, UEC,
CBP and Kembangan also counted. Pass through or loop also
counted.
Stadium also counted
If you disregard all the services that go to the above towns and
areas, then the current smallest SBS service number that doesn't go
anywhere near has to be 50.