Problem 6a rle.py: Run length compression [10 points] Write a function rle() that takes a list as input and returns another list with its run length encoding. As always, the input list should not be modified in any way.

Problem 6b rle.py: Run length decompression [10 points] Write a function unrle() that takes the run length encoding as input and returns the original list. This is the inverse of the previous function (i.e., for anylistl,itsalwaystruethatunrle(rle(l)) == l).Onceagain,theinputlistshouldnotbemodifiedinany way.

Note: You can assume that all values in the encoding are immutable (i.e., you do not need to worry about making copies of the value component of each run).