Contest: Task: Related: TaskB

Score : $100$ points

Print the circumference of a circle of radius $R$.

- $1 \leq R \leq 100$
- All values in input are integers.

Input is given from Standard Input in the following format:

$R$

Print the circumference of the circle. Your output is considered correct if and only if its absolute or relative error from our answer is at most $10^{-2}$.

1

6.28318530717958623200

Since we accept an absolute or relative error of at most $10^{-2}$, $6.28$ is also an acceptable output, but $6$ is not.

73

458.67252742410977361942