Mr. Smith is an avid landscaper and gardener, resulting in the most beautiful house on his block. This increases property values on his street, resulting in a positive consumption externality for his neighbors. Below is a graph of the private and social benefit and private cost of Mr. Smith's gardening. Calculate the deadweight loss caused by this positive consumption externality.
a = $29 b = $23 c = $17 d = $8 e = $2 f = $5