sentences:  The final cadenza of the fourth movement is very difficult, containing the typical, very awkward fast runs, with big leaps and passages requiring 4th finger independence.Arguably the most difficult section, albeit a very short one, is a series of quick leaps, first in the left hand in the stride piano style, and then in both hands - with the second-to-last leap spanning three octaves in the left hand and two octaves in the right hand, followed immediately by the final, fast leap, spanning four octaves in the left hand and two octaves in the right hand - at the very end of the piece.The section is brilliantly virtuosic, with the composer himself known to be able to play it exactly as written.