import java.math.BigDecimal;
import java.util.Scanner;
public class Shohizei {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		BigDecimal D = new BigDecimal(s.nextLong());
		BigDecimal p = new BigDecimal("1.08");
		s.close();
		System.out.println(D.multiply(p).toString());

	}

}