Just how much space will be required in each of these months is known. However,since these space requirements are quite different,it may be most economical to lease only the amount needed each month on a month-by-month basis. On the other hand,the additional cost for leasingspace for additional months is much less than for the first month,so it may be less expensive to lease the maximum amount neededfor the entire 5 months. Another option is the intermediate approach of changing the total amount of space leased (by adding a new leaseand/or having an old lease expire) at least once but not every month