I have been trying to calculate this problem and I have had a difficult time

Mr. Areola is planning to make an additional investment at the end of each year for his retirement in 20 years. Mr. Areola plans to invest $5,000 each year for the first 5 years, $8,000 each year for the next 5 years, and $ 12,000 each year for the remaining 10 years. If the rate of return of 11 percent can be earned in these investments, how much money will Mr. Areola have at the end of 20 years