For the given positive integer $n$ find the product $$ \left (1 + \dfrac{1}{1^2} \right ) \cdot \left (1 + \dfrac{1}{2^2} \right ) \cdot \ldots \cdot \left (1 + \dfrac{1}{n^2} \right )$$ \InputFile One integer $n\:(n \le 1000)$. \OutputFile Print the value of the product with $6$ decimal digits.