The length of the circle through the area of the circle

Problem

Write a program that calculates the length of a circle through the area of the circle.

The circle length from the known area of the circle can be calculated by the formula : \(L=\sqrt{S4\pi}\) , \(\pi\) - number of pi; \(S\) - area of the circle.

You can use built-in constants to get the exact value of pi.
In C++ you must write the following line at the beginning of your program #define _USE_MATH_DEFINES

In Python, you can use a constant from the math library math.pi

Input format
Given an one real number - area of the circle S (1 <= S <= 10^{3}).