A farm boy decides to take a trip in to the city. Times are hard and he has no money but he must stay in the city for 7 nights. He gets a room at an inn for 7 nights. The only thing he has that can be used for payment is a silver chain with 7 links in it. The inn keeper agrees that he will take it for payment. With a coule conditions, 1) he must pay for the room each night. The inn keeper will not take payments in advance. 2)The inn keeper also says that to perserve the value of the chain it cannot be cut more than twice. How will this farm boy pay for his room?