Name the maximum number of disc for bill gereghty
{'header': ['No. in series', 'No. Disc', 'Title', 'Directed by', 'Written by', 'Original air date', 'Length (minutes)'], 'page_title': '', 'page_id': '', 'types': ['text', 'real', 'text', 'text', 'text', 'text', 'real'], 'id': '1-15430606-1', 'section_title': '', 'caption': '', 'rows': [['Pilot', '1', '" Children of the Gods "', 'Mario Azzopardi', 'Jonathan Glassner & Brad Wright', 'July27,1997 ( Showtime )', '95'], ['2', '1', '"The Enemy Within"', 'Dennis Berry', 'Brad Wright', 'August1,1997 (Showtime)', '43'], ['3', '1', '"Emancipation"', 'Jeff Woolnough', 'Katharyn Michaelian Powers', 'August8,1997 (Showtime)', '44'], ['4', '2', '"The Broca Divide"', 'Bill Gereghty', 'Jonathan Glassner', 'August15,1997 (Showtime)', '44'], ['5', '2', '"The First Commandment"', 'Dennis Berry', 'Robert C. Cooper', 'August22,1997 (Showtime)', '44'], ['6', '2', '"Brief Candle"', 'Kenneth J. Girotti', 'Jeff F. King', 'September19,1997 (Showtime)', '44'], ['7', '2', '"Cold Lazarus"', 'Charlie Correll', 'Jeff F. King', 'August29,1997 (Showtime)', '44'], ['8', '2', '"Thor\'s Hammer"', 'Mario Azzopardi', 'Katharyn Michaelian Powers', 'September26,1997 (Showtime)', '44'], ['9', '3', '"The Torment of Tantalus"', 'Jonathan Glassner', 'Robert C. Cooper', 'October3,1997 (Showtime)', '44'], ['10', '3', '"Bloodlines"', 'Mario Azzopardi', 'Jeff F. King', 'October10,1997 (Showtime)', '44'], ['11', '3', '"Fire and Water"', 'Allan Eastman', 'Katharyn Michaelian Powers', 'October17,1997 (Showtime)', '44'], ['12', '3', '"The Nox"', 'Brad Turner', 'Hart Hanson', 'September12,1997 (Showtime)', '44'], ['14', '4', '"Cor-ai"', 'Mario Azzopardi', 'Tom J. Astle', 'January23,1998 (Showtime)', '44'], ['15', '4', '"Singularity"', 'Mario Azzopardi', 'Robert C. Cooper', 'October31,1997 (Showtime)', '44'], ['16', '4', '"Enigma"', 'Bill Gereghty', 'Katharyn Michaelian Powers', 'January30,1998 (Showtime)', '44'], ['17', '4', '"Tin Man"', 'Jimmy Kaufman', 'Jeff F. King', 'February13,1998 (Showtime)', '44'], ['18', '4', '"Solitudes"', 'Martin Wood', 'Brad Wright', 'February6,1998 (Showtime)', '44'], ['19', '5', '"There But for the Grace of God (1)"', 'David Warry-Smith', 'Robert C. Cooper', 'February20,1998 (Showtime)', '44'], ['20', '5', '"Politics (2)"', 'Martin Wood', 'Brad Wright', 'February27,1998 (Showtime)', '38']], 'name': 'table_15430606_1'}