using System;
public class Program
{
    public static void Main()
    {
        long yosan = long.Parse(Console.ReadLine() ?? string.Empty);
        int child = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] pass = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string a = Console.ReadLine() ?? string.Empty;

        long money = (yosan / 1000) * 1000;

        if(money / child >= 1000)
        {
            long mm = ((money / child) / 1000) * 1000;
            Console.WriteLine(mm);
        }
        else
        {
            Console.WriteLine(0); 
        }



    }
}