import java.util.Scanner;

public class Main {

	@SuppressWarnings("resource")
	public static void main(String args[]) {
		Scanner scanner = new Scanner(System.in);
		int n=scanner.nextInt();
		int a[]={1,4,2,8,5,7};
		if(n==0){
			System.out.print(0);
			return;
		}
		System.out.print("0.");
		for(int i=0;i<n;i++){
			System.out.print(String.valueOf(a[i%6]));
		}
		System.out.println();
	}
}