Task: Text to Code
Input (English): Step 1: For each row in actor table, find the corresponding rows in film_actor table.
Step 2: find the number of rows of each value of film_actor's actor_id in the results of step 1.
Step 3: find first_name of step 1 results with largest value in the results of step 2
Output (English): SELECT T1.first_name FROM actor AS T1 JOIN film_actor AS T2 ON T1.actor_id = T2.actor_id GROUP BY T2.actor_id ORDER BY Count ( * ) Desc LIMIT 1