There is a collection of $n$ squares with side $1$. How many different rectangles can be formed using these squares? Two rectangles are considered different if none of them can be rotated and moved to obtain the second one. During rectangle construction, its forbidden to deform the squares or to put any squares upon any other ones. \InputFile One integer $n~(1 \le n \le 10^9)$. \OutputFile Print the number of different rectangles that can be formed using squares. \includegraphics{https://static.e-olymp.com/content/c9/c9f5f4e73f94b44a06464b09ac1d53c261e321c8.gif}