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

public class No00000128_Main {

	public static void main(String[] args) throws IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		long n = Long.parseLong(br.readLine());
		int m = Integer.parseInt(br.readLine());

		System.out.println(((n / m) / 1000) * 1000);

	}
}