using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Programming
{
    class Program
    {
        static void Main(string[] args)
        {
            double N = double.Parse(Console.ReadLine());
            double M = double.Parse(Console.ReadLine());
            double ans = Math.Floor(N / M / 1000) * 1000;

            Console.WriteLine((decimal)ans);
        }
    }
}