Recall Merge Sort, in which a list is sorted by first sorting the left and right halves, and then merging the two lists.

We define the $\backslash$textit$\{3-$Merge Sort$\}$ algorithm, in which the input list is split into $$3$$

equal length parts $($or as equal as possible$),$ each is sorted recursively, and then the three lists are merged to create a final sorted list.