Who won stage 18?
{'header': ['Stage', 'Winner', 'General classification', 'Points classification', 'Mountains classification', 'Young rider classification', 'Team classification', 'Combativity award'], 'page_title': '2009 Tour de France', 'section_title': 'Classification leadership', 'caption': 'Classification leadership', 'rows': [['1', 'Fabian Cancellara', 'Fabian Cancellara', 'Fabian Cancellara', 'Alberto Contador', 'Roman Kreuziger', 'Astana', 'no award'], ['2', 'Mark Cavendish', 'Fabian Cancellara', 'Mark Cavendish', 'Jussi Veikkanen', 'Roman Kreuziger', 'Astana', 'Stef Clement'], ['3', 'Mark Cavendish', 'Fabian Cancellara', 'Mark Cavendish', 'Jussi Veikkanen', 'Tony Martin', 'Astana', 'Samuel Dumoulin'], ['4', 'Astana', 'Fabian Cancellara', 'Mark Cavendish', 'Jussi Veikkanen', 'Tony Martin', 'Astana', 'no award'], ['5', 'Thomas Voeckler', 'Fabian Cancellara', 'Mark Cavendish', 'Jussi Veikkanen', 'Tony Martin', 'Astana', 'Mikhail Ignatiev'], ['6', 'Thor Hushovd', 'Fabian Cancellara', 'Mark Cavendish', 'Stéphane Augé', 'Tony Martin', 'Astana', 'David Millar'], ['7', 'Brice Feillu', 'Rinaldo Nocentini', 'Mark Cavendish', 'Brice Feillu', 'Tony Martin', 'Astana', 'Christophe Riblon'], ['8', 'Luis León Sánchez', 'Rinaldo Nocentini', 'Thor Hushovd', 'Christophe Kern', 'Tony Martin', 'Ag2r-La Mondiale', 'Sandy Casar'], ['9', 'Pierrick Fédrigo', 'Rinaldo Nocentini', 'Thor Hushovd', 'Egoi Martínez', 'Tony Martin', 'Ag2r-La Mondiale', 'Franco Pellizotti'], ['10', 'Mark Cavendish', 'Rinaldo Nocentini', 'Thor Hushovd', 'Egoi Martínez', 'Tony Martin', 'Ag2r-La Mondiale', 'Thierry Hupond'], ['11', 'Mark Cavendish', 'Rinaldo Nocentini', 'Mark Cavendish', 'Egoi Martínez', 'Tony Martin', 'Ag2r-La Mondiale', 'Johan Van Summeren'], ['12', 'Nicki Sørensen', 'Rinaldo Nocentini', 'Mark Cavendish', 'Egoi Martínez', 'Tony Martin', 'Team Saxo Bank', 'Nicki Sørensen'], ['13', 'Heinrich Haussler', 'Rinaldo Nocentini', 'Thor Hushovd', 'Franco Pellizotti', 'Tony Martin', 'Team Saxo Bank', 'Heinrich Haussler'], ['14', 'Sergei Ivanov', 'Rinaldo Nocentini', 'Thor Hushovd', 'Franco Pellizotti', 'Tony Martin', 'Ag2r-La Mondiale', 'Martijn Maaskant'], ['15', 'Alberto Contador', 'Alberto Contador', 'Thor Hushovd', 'Franco Pellizotti', 'Andy Schleck', 'Astana', 'Simon Špilak'], ['16', 'Sandy Casar *', 'Alberto Contador', 'Thor Hushovd', 'Franco Pellizotti', 'Andy Schleck', 'Astana', 'Franco Pellizotti'], ['17', 'Fränk Schleck', 'Alberto Contador', 'Thor Hushovd', 'Franco Pellizotti', 'Andy Schleck', 'Astana', 'Thor Hushovd'], ['18', 'Alberto Contador', 'Alberto Contador', 'Thor Hushovd', 'Franco Pellizotti', 'Andy Schleck', 'Astana', 'no award'], ['19', 'Mark Cavendish', 'Alberto Contador', 'Thor Hushovd', 'Franco Pellizotti', 'Andy Schleck', 'Astana', 'Leonardo Duque'], ['20', 'Juan Manuel Gárate', 'Alberto Contador', 'Thor Hushovd', 'Franco Pellizotti', 'Andy Schleck', 'Astana', 'Tony Martin'], ['21', 'Mark Cavendish', 'Alberto Contador', 'Thor Hushovd', 'Franco Pellizotti', 'Andy Schleck', 'Astana', 'Fumiyuki Beppu']]}