How many episodes have been directed and written by Darrick Bachman and Brett Varon? 
{'header': ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Storyboarded by', 'Original air date', 'Production code'], 'page_title': '', 'section_title': '', 'caption': '', 'rows': [['21a', '1a', '"Panini for President"', 'Juli Hashiguchi', 'William Reiss', 'William Reiss', 'November6,2008', '202a'], ['22b', '2b', '"The Flying Flinger Lingons"', 'Eddy Houchins', 'C.H. Greenblatt and Dave Smith', 'Dave Smith', 'November13,2008', '203b'], ['24', '4', '"The Arborians"', 'Kris Sherwood', 'C.H. Greenblatt, William Reiss and Alex Almaguer', 'Alex Almaguer', 'November27,2008', '201a'], ['26b', '6b', '"The Catch Phrase"', 'Majella Milne', 'Danielle McCole, C.H. Greenblatt and Brett Varon', 'Brett Varon', 'December11,2008', '205b'], ['27a', '7a', '"The Hot Date"', 'Majella Milne', 'Darrick Bachman, C.H. Greenblatt and Alex Almaguer', 'Alex Almaguer', 'February12,2009', '206a'], ['28b', '8b', '"Won-Ton Bombs"', 'Mike Milo', 'Darrick Bachman, C.H. Greenblatt and Brett Varon', 'Brett Varon', 'April26,2009', '207b'], ['29a', '9a', '"The Big Hat Biddies"', 'Kris Sherwood', 'Darrick Bachman, C.H. Greenblatt and Ian Wasseluk', 'Ian Wasseluk', 'April26,2009', '208a'], ['30b', '10b', '"The Trouble with Truffles"', 'Mike Milo', 'Brett Varon', 'Brett Varon', 'June11,2009', '210b'], ['31', '11', '"The Dinner Theater"', 'Kris Sherwood and Eddy Houchins', 'Kevin A. Kramer, C.H. Greenblatt and William Reiss', 'William Reiss', 'June25,2009', '211'], ['32a', '12a', '"Kid Shnitzel"', 'Eddy Houchins', 'Kevin A. Kramer, C.H. Greenblatt and Ian Wasseluk', 'Ian Wasseluk', 'July6,2009', '209a'], ['33a', '13a', '"Big Ball"', 'Mike Milo', 'Darrick Bachman, C.H. Greenblatt and Alex Almaguer', 'Alex Almaguer', 'July10,2009', '212a'], ['36a', '16a', '"Paint the Town"', 'Eddy Houchins', 'Kevin A. Kramer, C.H. Greenblatt and Alex Almaguer', 'Alex Almaguer', 'August6,2009', '215a'], ['36b', '16b', '"The Blackout"', 'Kris Sherwood', 'Kristina Baranovich and Peter Browngardt', 'Peter Browngardt', 'August6,2009', '215b'], ['37b', '17b', '"The Chain Recipe"', 'Majella Milne', 'Darrick Bachman and Brett Varon', 'Brett Varon', 'August13,2009', '216b'], ['38b', '18b', '"Sheboodles"', 'Eddy Houchins', 'Darrick Bachman, C.H. Greenblatt and William Reiss', 'William Reiss', 'August20,2009', '217b']]}