- return '<li><span data-solution="%s" data-no="%s" class="question-piece draggable handle add-li">%s</span>' % (element.attrib['rozw'], self.piece_counter, self.piece_counter), '</li>'
+ return '<li><span data-solution="%s" data-no="%s" class="question-piece draggable handle add-li">%s</span>' % (element.attrib.get('rozw', ''), self.piece_counter, self.piece_counter), '</li>'