<?php
// Here your code !

$n_yen= trim(fgets(STDIN));
$menbers= trim(fgets(STDIN));

$y=$n_yen-$n_yen%1000;  //1000 後ろ３桁０００に

$ans=(($y/1000)-($y/1000)%$menbers)/$menbers;

//echo $ans.PHP_EOL;
$ans=$ans*1000;

echo $ans.PHP_EOL;

//10000000000000000