class Program
{
    static void Main(string[] args)
    {
        string inputMone = Console.ReadLine()!;
        string inputCount = Console.ReadLine()!;

        long mone = long.Parse(inputMone);
        long count = long.Parse(inputCount);

        long ans = mone / count;

        if (ans < 1000)
        {
            ans = 0;
        }
        else if(ans % 1000 != 0)
        {
            long remainder = ans % 1000;
            ans = ans - remainder;
        }

        Console.WriteLine(ans);
    }
}