What is the highest track number?
{'header': ['Track #', 'Song', 'Singers', 'Picturization', 'Length', 'Lyricist'], 'page_title': 'Azhagiya Tamil Magan', 'section_title': 'Soundtrack', 'caption': 'Soundtrack', 'rows': [['1', '"Ellappugazhum"', 'A. R. Rahman', 'Vijay', '5:31', 'Vaali'], ['2', '"Ponmagal Vandaal"', 'Mohammed Aslam , Ember Phoenix', 'Vijay, Shriya', '3:05', 'Alangudi Somu'], ['3', '"Nee Marilyn Monroe"', 'Benny Dayal , Ujjayinee', 'Vijay, Namitha', '6:14', 'Na. Muthukumar'], ['4', '"Valayapatti Thavile"', 'Naresh Iyer , Ujjayinee , Madhumitha', 'Vijay, Shriya', '5:44', 'Na. Muthukumar'], ['5', '"Kelamal Kaiyile"', 'Sriram Parthasarathy , Saindhavi', 'Vijay, Shriya', '5:27', 'Thamarai']]}