import java.util.*;
import java.io.*;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter ou = new PrintWriter(System.out);
		int k = Integer.parseInt(sc.next());
		double s = 0;
		for(int i = 1 ; i <= 10 ; i++){
			s += Math.sin(k * i) / Math.pow(i , i);
		}
		ou.println(s);
		sc.close();
		ou.flush();
	}
}