Problem 1 (1 pt). Consider the following initial 2-3-4 tree: We will delete keys from the tree by using the following rules: Rule 1: As you go down the tree and the next-node is a minkey node (doesn't have extra keys): - If the next-node has a left sibling with an extra key, right-rotate a key into the next-node from the sibling. - Otherwise, if the next-node has a right sibling with an extra key, left-rotate a key into the next-node from the sibling. - Otherwise, if there is a left sibling (and no extra key), merge the next-node with its left sibling. - Otherwise, merge the next-node with its right sibling (that has no extra key). We can express this rule with a table: Rule 2: Replacement keys are predecessors. Here is an example