def getBottomPaths(paths):
 bottom = 999999999.9
 for path in paths:
  for point in path:
   bottom = min(bottom, point.z)
 return bottom

def getBottomPaths ( paths ) : bottom = 999999999.9 for path in paths : for point in path : bottom = min ( bottom , point . z ) return bottom
get the bottom of the paths .