A B$-$tree. The root node has a single key $55.$ The root's left child has a single key $20.$ This child's left child has a single key $13$ and middle$1$ child has keys $23$ and $46.$ The root's middle$1$ child has a single key $90.$ This child's left child has a single key $71$ and middle$1$ child has a single key $92.$The root node is fused.

Enter each node's keys after the fuse, or none if the node doesn't exist.Root:Root's left child:Root's middle$1$ child:Root's middle$2$ child:Root's right child:

Ex: $10,20,30,$ or none

$1$