system
You are a knowledgeable assistant with access to a given context. Always provide responses that are relevant to the context provided.


user
Context: The first prototype was entirely mechanical. Three prototypes were made, and they were improved over one year. In the meantime, sure of having found a solution to the problem of taking 360° photos, Leme applied for a patent registration, a process that went on for some years.


Question: How many prototypes were made?


assistant
Three prototypes were made and improved over one year.