Tim takes out a loan of Land agrees to pay it back in equal size monthly payments over the next 25 years. Payments of size 500 are made at the end of each month and Tim is charged an annual nominal rate of 12% compounded monthly. After 15 years of payments (i.e. 180 payments), how much interest (in total) has Tim paid? Give your answer rounded to the nearest whole number (i.e. X)