Which of the following alternatives is superior over a 20-year period if the interest rate is 6.25%, and inflation rate is 3.25%?

\begin{tabular}{lll} & alternative A & alternative B \\ \hline type & brick & wood \\ life & 30 years & 10 years \\ initial cost & $1800 & $450 \\ maintenance & $5/ year & $20/ year \end{tabular}