import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No0285 {
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		BufferedReader br= new BufferedReader(new InputStreamReader(System.in));
		int D = Integer.parseInt(br.readLine());
		double price = D * 1.08;
		
		System.out.println(price);
	}
}