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2121. Intersection of Parabolas

Time limit: 1.0 second
Memory limit: 64 MB
Find the area of the region bounded by the following two parabolas: y=(xa)2 and x=(ya)2.

Input

The first line contains a single integer a (1 ≤ a ≤ 1018).

Output

Print the answer to the problem with exactly 10 digits after the decimal point, using the standard rounding rules.

Sample

inputoutput
2
7.6666666667
Problem Author: Alexey Danilyuk
Problem Source: Petrozavodsk Summer 2018. t.me/umnik_team Contest