How many role-playing games did Microsoft Game Studios publish?
role-playing game refers to genre_name = 'Role-Playing'; Microsoft Game Studios refers to publisher_name = 'Microsoft Game Studios'
SELECT COUNT(T3.id) FROM publisher AS T1 INNER JOIN game_publisher AS T2 ON T1.id = T2.publisher_id INNER JOIN game AS T3 ON T2.game_id = T3.id INNER JOIN genre AS T4 ON T3.genre_id = T4.id WHERE T4.genre_name = 'Role-Playing' AND T1.publisher_name = 'Microsoft Game Studios'