In the game KeyForge, each deck is completely unique. There are over 104,000,000,000,000,000,000,000,000 possible decks! Each deck contains 3 different houses (factions) chosen from a set of 7 possible houses. Assuming we only care if a house is in a deck or not, how many decks do you need to have one deck with each possible set of houses? (Show process and work out to a numeric answer)