public class No_128 {

	public static void main(String[] args) {
		java.util.Scanner sc = new java.util.Scanner(System.in);
		long otoshidama = sc.nextLong();
		long paperMoney = otoshidama / 1000;
		long child = sc.nextLong();
		
		System.out.println(paperMoney / child * 1000);
		sc.close();
		

	}

}