CREATE TABLE table_203_413 (id DECIMAL, "rank" TEXT, "city" TEXT, "population" DECIMAL, "area\ ( km2 ) " DECIMAL, "density\ ( inhabitants/km2 ) " DECIMAL, "altitude\ ( mslm ) " DECIMAL)

which city is the most densely populated ?
SELECT "city" FROM table_203_413 ORDER BY "density\n(inhabitants/km2)" DESC LIMIT 1
SELECT "city" FROM "table_203_413" ORDER BY "density\n(inhabitants/km2)" DESC NULLS LAST LIMIT 1