A father plans to open a planned savings account to pay for his daughter's college. Now her daughter is 12 years old. He plans to apply to college in 6 years from now, and it will take her 4 years to complete the course. Now the annual cost (covering all necessities, food, clothing, tuition, institutional, books, transportation and so on) is IDR 125 million/year, and the inflation rate for all costs is estimated at 5%/year. His daughter has just received a gift for her 12th birthday from her grandfather, a savings of IDR 50 million with a bank interest rate of 0.5% per month which will be used to help pay for college in the future. The rest of the cost will be met from the money his father will keep in his savings account. The savings deposit will be made in the same amount every month until her daughter enters the college.