import java.util.Scanner;


public class Main_yukicoder221 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        double g = 0.01 * (10000 - n) + 0.99 * n;
        double ret = 0.01 * (10000 - n) / g;

        System.out.printf("%.3f\n", ret * 100);
        
        sc.close();
    }
}