Mike likes to draw triangles, but he does it in an unusual way. First he draws an arbitrary triangle, then divides each side into $n$ equal parts and draws through the partition points the lines parallel to sides of triangle. As a result he gets a number of triangles equal to each other. Help Mike to find the maximum number of identical triangles in his final picture. \includegraphics{https://static.eolymp.com/content/e5/e5976b95bb58c51c9e5a2dfeeabbc5d4bba83473.gif} \InputFile One integer $n~(0 < n < 2 \cdot 10^9)$. \OutputFile The maximum number of triangles equal to each other.