The block distance from oldText to newText is defined as the least number of block insertions in oldText that are needed to make it equal to newText. A block insertion into oldText is the insertion of any string at any position. For example, if oldText is "herld" a possible block insertion is inserting "llo wo" before the 'r' which will give "hello world".
As an example, if oldText is "hello goodbye" and newText is "hello, how are you? goodbye have a nice day", the block distance between them is 2 because by inserting ", how are you? " and " have a nice day" properly, we can make oldText equal to newText.
You will be given oldText and newText as two Strings. You must first concatenate all the elements within each of them to form two long strings, and then return the block distance between them. If there is no way to make oldText equal to newText using only block insertions, return -1.