Complete flatten that takes a list of lists (which can have lists ad infinitum) and flatten them into a one dimensional list.

So this input:

[1, [2, 3], [4, 5, [6, 7, [8, 9, 10]]]]

... should generate this output:

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Make sure you support both lists and tuples. You probably want to use recursion here ... have fun!