import java.io.*;
import java.util.*;
import java.math.*;

class Main128 {
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		long n = Long.parseLong(br.readLine());
		long m = Long.parseLong(br.readLine());
		
		long d = n / m;
		System.out.println(d - (d % 1000));
	}
}