A. Ancient Math
time limit per test
1 second
memory limit per test
1024 megabytes
input
standard input
output
standard output

Squaring the circle is an age old problem. For millennia, people have sought to construct a square whose area is the same as a given circle. In 1882, Lindemann proved that $$$\pi$$$ is transcendental. As a corollary, it was then known that squaring the circle is impossible. Although there have been many claims to successfully squaring the circle, none has succeeded to this day...

Your mission, should you choose to accept it, is to square the circle.

Input

The first and only line of input contains a single integer $$$r$$$ ($$$1 \le r \le 1000$$$), which is the radius of the circle.

Output

The only line of output should contain a single real number, which is the side length of the square whose area is the same as the given circle. The output will be considered correct if the absolute or relative error is less than $$$10^{-4}$$$. Namely, if your answer is $$$a$$$ and the jury's answer is $$$b$$$, then your answer is accepted if $$$\frac{|a - b|}{\max(1,|b|)} \le 10^{-4}$$$.

Examples
Input
1
Output
1.7724538509
Input
42
Output
74.4430617380