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 x = Integer.parseInt(sc.next()) - 1;
		double q = 0;
		for(int i = 1 ; i <= Math.pow(10 , 6) ; i++){
			double u = Math.pow(10 , 9) / (i * Math.pow(i + 1 , x));
			if(u > 0) q += u;
		}
		q /= 1000;
		ou.println((int)q);
		sc.close();
		ou.flush();
	}
}