A list of tree species needs to be sorted into descending alphabetical order using a merge sort algorithm.

Here are the five sublists created at the end of the initial splitting process:

[Rowan]     [Birch]     [Willow]     [Oak]     [Maple]

It will require three passes to merge these sublists back into a single sorted list in descending alphabetical order.

Complete the three merge passes by filling in the missing sublists.

• Pass 1: [ Rowan, Birch ], [ Willow, Oak ], [ Maple ]

• Pass 2: [ __________________________________ ], [ Maple ]

• Pass 3: [ __________________________________________ ]