import java.util.Scanner;

import static java.lang.Math.*;

public class Main {
    public static void  main(String[]args){
        Scanner in = new Scanner(System.in);
        System.out.print("x=");
        double x = in.nextDouble();
        double S = 0;
        int k = 1;
        do {
            S += exp(-k * x) / (k + 1);
            k++;
        }while (k <=8 );
            System.out.printf("При x=%.2f, S=%.8f", x, S);
    }
}