Now these cities shared trade routes. They're going to share languages and technologies and religious customs. But in a sense, they're like separate little countries all by themselves. They're going to have their own kings in a sense and rulers and different personalities that are going to fight with each other. But they are under the umbrella of having these commonalities, things in common that make them all Sumerians. Now we also are going to need for a civilization specialized workers. And certainly having city-states and different jobs, you have to build walls and you have to irrigate and raise animals and there's going to be people that are going to write things down and invent new things.