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


public class Y428 {
	Y428() throws Exception {
		Scanner in = new Scanner(System.in);
		PrintStream out = new PrintStream(System.out);
		
		int m = in.nextInt();
		
		BigDecimal D = new BigDecimal("0.1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991");
		
		BigDecimal A = D.multiply(BigDecimal.valueOf(m));
		
		out.println(A.toString());
	}

	public static void main(String argv[]) throws Exception {
		new Y428();
	}
}