import java.io.*;

// The "Template" class.
public class IProfit
{
    public static void main (String[] args) throws IOException
    {

	//Variables
	double profit, copies1, copies2;
	long copies3;



	// Open up the input and output file for IO purpose
	FileReader inFile = new FileReader ("DATA11.txt");
	FileWriter outFile = new FileWriter ("OUT11.txt");

	// Link the input and output file for
	BufferedReader in = new BufferedReader (inFile);
	BufferedWriter out = new BufferedWriter (outFile);

	String line;

	// Keep reading as long as not end of file (eof)
	while ((line = in.readLine ()) != null)
	{
	    profit = Double.parseDouble(line);  
	
	//System.out.println (line);



	    // //Input
	    // c.print ("Please enter the preferred profit: ");
	    // profit = c.readDouble ();
	    // c.println ("");

	    //Process
	    copies1 = (long) (profit / (0.693));

	    copies2 = Math.ceil (copies1 / 1000);
	    copies3 = (long) (copies2 * 1000);



	    //Output
	   // c.print ("The number of copies needed to be sold to the nearest 1000: " + copies3);
	    out.write(copies3+"");
	    out.newLine();

	    //out.write (str);
	    //out.newLine ();
	}

	// Close input and output file
	in.close ();
	out.close ();

    } // main method
} // End of Class