A high quality insulation doubles the cost of a traditional insulation (assume $X), which is fully loaned for q years with an annual interest rate of m (in %). This results in an annual energy saving of n (in %) (assume the total annual energy cost is $Y). Assume the average monthly energy cost growth rate is p (in %). Please detive the equation to determine the month when the energy saving is over the extra loan payment due to the use of high quality insulation. Calculate the number if X=100,000, Y=20,000, m=8%, n=3%, p=0.4%, q=30