Among the best actors, how many of them got a rating of 5 to the movies they starred?
SELECT COUNT(T1.actorid) FROM actors AS T1 INNER JOIN movies2actors AS T2 ON T1.actorid = T2.actorid INNER JOIN u2base AS T3 ON T2.movieid = T3.movieid WHERE T1.a_quality = 5 AND T3.rating = 5