( 0 2 4 2445 l( 1 0 3 1919 l( 3 0 7 1321 l( 5 -1 -1 732 l r ) r( 6 -1 -1 589 l r ) ) r( 4 -1 -1 598 l r ) ) r( 2 -1 -1 526 l r ) )
5 20
