import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author silviase
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        seven solver = new seven();
        solver.solve(1, in, out);
        out.close();
    }

    static class seven {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            // 10^k の割合がxだったとする(余りがt)
            // 次の桁は10x + floor(10t/7)個,あまりは10t%7
            // 商をならべていけばいい
            int n = in.nextInt();
            if (n == 0) {
                out.println(0);
            } else {
                StringBuilder sb = new StringBuilder("0.");
                int mod = 1;
                for (int i = 1; i <= n; i++) {
                    sb.append((mod * 10) / 7);
                    mod = (mod * 10) % 7;
                }
                out.println(sb);
            }


        }

    }
}