def get_distance_traveled():
return state['<STR_LIT>']<EOL>
Returns a number like 123, representing the distance that the brush has traveled
    since the last time that it was dipped in paint or water.

    NOTE: Only tracks movement triggered by calls to the `move_forward()` function.
    Movement caused by `move_to()` is _not_ recorded.

    This number represents the number of "steps" that the brush has traveled, not the number
    of inches or centimeters; you'll have to do some experimentation on your own to figure
    out e.g. how many centimeters 100 steps is equal to.