Question: How many different actors from the Second national tour year 2 played the character played by Oliver Tompsett from the original West End cast?
Schema: create table table_19529639_3 (second_national_tour_year_2 varchar, original_west_end_cast varchar, PRIMARY KEY (second_national_tour_year_2))
SQL: select count(second_national_tour_year_2) from table_19529639_3 where original_west_end_cast = "oliver tompsett"