I reckon the following are all the towns in West Sussex;- Worthing, Crawley, Burgess Hill, East Grinstead, Haywards Heath, Southwick, Shoreham-by-sea, Littlehampton, Horsham, Arundel, Bognor Regis...
999
999'000'000'000'000'000'000'000'0mile
263.7 miles (424.38 kilometres)
quite alot considering they come from different countries