#!/usr/bin/perl

use strict;
use warnings;

my $n = <>;
my $m = <>;

$n /= 1000;
my $ans;
if($n < $m) {
	$ans = 0;
} else {
	$ans = $n % $m;
	$ans = $n - $ans;
	$ans = $ans / $m;
	$ans *= 1000;
}

print "$ans\n";

exit;