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 n = sc.nextInt(); if(n == 0) ou.println(0); else{ double yono = 0; for(int i = 1 ; i <= 20 ; i++){ yono += Math.sin(i * n) / (long)Math.pow(i , i); } ou.println(yono); } ou.flush(); } }