import java.util.Scanner;

public class Main {
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        while(sc.hasNext()){
        	long n=sc.nextLong();
        	long m=sc.nextLong();
        	
        	if(n/m<1000) System.out.println(0);
        	else{
        		long temp=n/1000/m;
        		temp=temp*1000;
        		System.out.println(temp);
        	}
        }
    }
}