import java.util.Scanner;


class No_128 {
	public static void main(String args[]) {
		Scanner stdIn = new Scanner(System.in);

		long budget = stdIn.nextLong();
		long persons = stdIn.nextLong();

		long count = 0;
		while ( true ) {
			if ( count * (persons * 1000) == budget ) {
				break;
			}
			if ( count * (persons * 1000) > budget ) {
				count--;
				break;
			}
			count++;
		}
		System.out.println(1000 * count);
	}
}