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

public class Main {

	public static void main(String[] args) {
	      BufferedReader stdReader =new BufferedReader(new InputStreamReader(System.in));
	      try {
	    	int n = Integer.parseInt(stdReader.readLine());
	    	int m = Integer.parseInt(stdReader.readLine());
	    	int num = 0;
	    	while((num+1)*m*1000 <= n) num++;
	    	System.out.println(num*1000);
	      } catch (IOException e) {
			e.printStackTrace();
	      }
	}

}