Sum of Squares

Given a positive integer n, compute the sum of the squares of the first n natural numbers. The mathematical formula for this sum is given by: $$S = \sum_{i=1}^{n} i^2 = \frac{n(n+1)(2n+1)}{6}$$.

inputFormat

The input consists of a single positive integer n.

outputFormat

Output the calculated sum of squares.

sample

1

1