Dynamo for Revit: Creating a hollow cylindrical surface __dyanmo

How to create a hollow cylindrical surface using the dynamo for Revit.
The effect is as follows:

Right-click on the New tab to open more clearly. (The nodes have been grouped and commented)

Code in the Python node (the largest of the surface area of the input):

Import CLR
CLR. AddReference (' Protogeometry ') from
Autodesk.DesignScript.Geometry Import *
#The inputs to this node would be stored as a list in the variables.
Dataenteringnode = in
surfaces = in[0]

index = 0;
Maxarea = 0.0;
Maxindex = 0;
For surface in surfaces:
    if surface. Area > Maxarea:
        maxarea = surface. Area
        Maxindex = Index
    = index + 1

#Assign your output
to the out variable. out = Maxindex