Task: Text to Code
Input (English): Step 1: find the medicine's id of medicine table for which FDA_approved equals No.
Step 2: find the number of rows in enzyme table whose enzyme's id not one of the results of step 1
Output (English): SELECT Count ( * ) FROM enzyme AS T1 WHERE T1.id NOT IN ( SELECT T2.id FROM medicine AS T2 WHERE T2.FDA_approved = "No" )