Question: Vítor Vianna is a Brazilian mixed martial artist, who has competed in mixed martial arts events in Brazil, Holland, and in the United States, this ranking is due to certain fights, of which type, that he has participated in which term used in combat sports such as boxing and mixed martial arts to describe a weight limit for odd class fights?
{'answer': 'Catchweight', 'supporting_facts': [['Vitor Vianna', 3], ['Catchweight', 0]]}