Sink or Swim

You will be given a list of lines that look like this:

### <   >    ### <<>><  ##

The characters mean the following:

• < are rocks that sink left
• > are bubbles that float right. Cannot pass rocks.
• # are walls
• is water (empty space)

Rocks can not pass bubbles, if a bubble is trapped next to a rock, the rock will always push the bubble down regardless of the number of bubbles.

Output the final state of the water column.

In this case, that would be ###< >###<<>>< ##

You may assume no bubbles or rocks can escape.

A few more examples:

• #<> # becomes #< >#
• # >< # becomes #>< #
• # >>>>>>>>>< becomes #>>>>>>>><