Problem:
Score : 100 points

Problem Statement

Given is an integer r.

How many times is the area of a circle of radius r larger than the area of a circle of radius 1?

It can be proved that the answer is always an integer under the constraints given.

Constraints

1 \leq r \leq 100

All values in input are integers.

Input

Input is given from Standard Input in the following format:

r

Output

Print the area of a circle of radius r, divided by the area of a circle of radius 1, as an integer.

Sample Input 1

2

Sample Output 1

4

The area of a circle of radius 2 is 4 times larger than the area of a circle of radius 1.

Note that output must be an integer - for example, 4.0 will not be accepted.

Sample Input 2

100

Sample Output 2

10000

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;

namespace A___Circle
{
    class Program
    {
        static void Main(string[] args)
        {
            var r = int.Parse(Console.ReadLine());
            Console.WriteLine(r * r * Math.PI / Math.PI);
        }
    }
}