package yukicoder;
import java.math.BigDecimal;
import java.util.Scanner;
public class Main{
	public static void main(String[] args)throws Exception{
		new Main().solve();
	}
	void solve(){
		Scanner sc=new Scanner(System.in);
		BigDecimal d=new BigDecimal(sc.next());
		System.out.println(d.multiply(new BigDecimal("1.08")));
	}
}