Sum of squares P36668

Write a program that reads a natural number $n$, and prints the result of the following sum: $$1^2 + 2^2 + \dots + (n-1)^2 + n^2 .$$

Input

Input consists of a natural number $n$.

Output

Print the sum of the first $n$ squares: $\sum_{i=1}^{n} i^2$.

Observation

The summation has a closed formula, so a loop would not be necessary to solve this exercise.