Problem:
Score : 100 points

Problem Statement

Print the circumference of a circle of radius R.

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 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}.

Sample Input 1

1

Sample Output 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.

Sample Input 2

73

Sample Output 2

458.67252742410977361942

Solution in Java (OpenJDK 11.0.6) (judge verdict: Runtime Error)

//package atcoder;
 
import java.util.*;
 
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int A[] = new int [N-1];
		for(int i=0;i<N-1;i++) {
			A[i] = sc.nextInt();
		}
		Map<Integer,Integer> map = new HashMap<>();
		for(int i=1;i<=N;i++) {
			map.put(i,0);
		}
		for(int j=0;j<N-1;j++) {
			map.put(A[j],map.get(A[j])+1);
		}
		for(Integer value : map.values()) {
			System.out.println(value);
		}
	}
}

/*public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String N = sc.next();
		char n[] = new char[3];
		for(int i=0;i<3;i++) {
			n[i] = N.toCharArray();
		}
	}
}*/