Rubik's Cube UK championship under way in Leicester
Hundreds of people are competing at a Rubik's Cube championship at the University of Leicester.
Challenges at the two-day event include solving the cube blindfolded and finishing the puzzle using feet instead of hands.
The world record for solving the puzzle on a standard cube was set last year by Mats Valk in 5.55 seconds.
The Rubik's Cube was invented in 1974 by Hungarian professor Ernő Rubik.
Competitor Billy Jeffs said: "You just have to learn how to recognise patterns and then you use short algorithms to apply to those patterns to solve them and then when you have learnt those methods you find learn better methods to get faster.
"Even the world champion will not know everything about this cube - you can never stop learning."
The world record for solving the cube with one hand is 9.03 seconds, set by Feliks Zemdegs of Australia.
The traditional cube has six faces each with three squares by three. Every face is a different colour - white, red, blue, orange, green and yellow.
The challenge is to finish with each side a single colour.