Mister Greenjeans wants to borrow $4,000,000 to purchase farm land to grow soy beans. He has approached the Agriculture Services division at his bank to arrange a farm mortgage. The bank has quoted him a rate of 5%. Mister Greenjeans wants to make quarterly payments of $77,345.68. He also anticipates that he will have to borrow an additional $750,000 after 12 years for land improvement costs. This extra principal will be added to the balance owing on the mortgage. How long will it take Mister Greenjeans to pay off the mortgage? (Express the answer in quarters.)