Therefore, more buildings were built in the Han Dynasty than in the Ming Dynasty (2-1.27)/1.27 = 73/127.

So the Ming Dynasty built 3650/(73/127) = 3650 *127/73 = 6350 km.

So the Han Dynasty built 6350 * 2/1.27 =10000 km.

The Qin Dynasty built 10000/2=5000km.