4. Eight people sit at a round table. Three of these people are children. All seating configurations are equally likely. You get paid a dollar for each pair of children that sit next to each other (i.e., you can get paid up to 2 dollars (you get paid 2 dollars if three children sit in a row, as there are two pairs of children sitting next to each other in this case)). Find the expectation of the amount of money that you'll get paid.