import java.math.BigDecimal;
import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext()){
			BigDecimal d=sc.nextBigDecimal();
			d=d.multiply(BigDecimal.valueOf(1.08));
			System.out.println(d.toPlainString());
		}
	}
}