Rubik's Cube World Championship

A blindfolded participant competes in the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

Judges watch Hong Yan Chan, 4, using her feet to solve a Rubik's Cube during the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

A competitor solves a Rubik's cube using his feet during the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

Participants attend the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

A competitor solves a Rubik's cube before he competes in the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

Competitors solve Rubik's cubes using their feet during the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

Competitor Yehude Cananza of Peru practices solving a Rubik's Cube while blindfolded, during the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

Blindfolded participants compete in the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

Participants attend the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker

Blindfolded participants compete in the Rubik's Cube World Championship in Sao Paulo, Brazil, July 17, 2015. REUTERS/Paulo Whitaker