The below table shows the contractor's monthly revenue for constructing a small house which will take 6 months to erect. The contractor prepares an invoice and submits it every two months and gets paid one month later. If the advance payment is 18 % of total revenue, retention 16%, and Mark-up 20%. TIME (Month) 1 2 3 45 6 Monthly Revenue 29 55 27 37 37 47 The amount of the final payment (in thousands of Riyals) that the contractor receives is