Inventors' Fair [Kaladesh Prerelease Promos]

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle your library. Activate this ability only if you control three or more artifacts.