import java.util.*;
import java.util.Map.Entry;
import java.math.*;
import java.awt.geom.*;
import java.io.*;
      
      
public class Main {	

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigDecimal bd = sc.nextBigDecimal();
		bd = bd.multiply(new BigDecimal("1.08"));
		System.out.println(bd.toString());
	}
		
}