Cody and Riley are building their first home together. They got a construction loan of $122,361, which will be rolled over to a conventional 30-year mortgage when the house is completed in 10 months. They will be charged simple interest of 1/2% per month on the construction loan (not making any payments until the first payment of the conventional loan). The 30-year mortgage will carry a 4.6% interest rate with monthly payments. What is the monthly mortgage payment they will make?