Sphere Volume

Problem Description

For a sphere of radius $r$, its volume is given by $V=\frac{4}{3}\pi r^3$.

Given $r$, compute $V$.

Input Format

A single non-negative real number not exceeding $100$, i.e. the sphere's radius, of type double.

Output Format

A single real number, the volume of the sphere, kept to 2 decimal places.

Sample Input

4

Sample Output

268.08

Hint

• Formula: $V = 4/3 \times \pi \times r^3$. Three pitfalls to check yourself: ① what is the value of 4/3? ② is the precision of $\pi$ good enough (same issue as the pi problem)? ③ how do you write $r^3$?
• Keep 2 decimal places.
• Verify with the sample: 4 → 268.08.