Walmart is laying off cashiers, and increasingly adopting the policy where customers must use self checkout or pay a fee. Jason Clarke is the manager of a Walmart. There are 20 cashiers and 8 self-checkout stations in this store to serve 1000 customers every hour. if the MRTS at this point is 0.2 (capital is on the vertical axis of isoquant map) the Jason would be willing to lay off ________ cashiers for one more self checkout station in order to maintain current service.