Typos

My book is based way in the future, where almost the entire world was destroyed by hurricanes, drouts, earthquakes.etc Although a certain amount of people have survived and have been surviving in the city of Chicago with a wall keeping them on the inside, and what ever is left, outside. The whole city is broken in to 4 sections so that everyone will know what to do. There is the kind people. They grow the food. The hunters. They are like the police. The builders. They build the city more and more. And the brave. They run outside the walls to get supports for all the others. Each year, on the same day, for all 18 years olds there is a test that you will take to find out who you are. You have no say in changing who you become. There are, however, people who don't fit in anywhere. Those people are called typos. They are seen as a mistake to society. They are trained for five days and then sent outside the gates. They must make it back in five days, or be left outside forever...