import java.util.*;

public class Main {
   public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        if (n == 0) {
            System.out.println(0);
            return;
        }
        StringBuilder sb = new StringBuilder("0.");
        int cur = 10;
        for (int i = 0; i < n; i++) {
            sb.append(cur / 7);
            cur = (cur % 7) * 10;
        }
        System.out.println(sb);
    }
}