import clr
clr.AddReference("RevitAPI")
import Autodesk
from Autodesk.Revit.DB import *
from System.Collections.Generic import *

clr.AddReference('ProtoGeometry')
from Autodesk.DesignScript.Geometry import *

clr.AddReference("RevitNodes")
import Revit
clr.ImportExtensions(Revit.Elements)

clr.ImportExtensions(Revit.GeometryConversion)

clr.AddReference("RevitServices")
import RevitServices
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
from System.Collections.Generic import *

doc = DocumentManager.Instance.CurrentDBDocument

mat=UnwrapElement(IN[0])
matid = UnwrapElement(IN[0]).StructuralAssetId
density=(doc.GetElement(matid).GetStructuralAsset().Density*35.314666666666)

OUT= density