<?php
function declOfNum($num, $titles) {
$cases = array (2, 0, 1, 1, 1, 2); return $titles[($num%100>4 && $num%100<20)?
2 : $cases[min($num%10, 5)]]; }
$allCount = 51;
$endWord = declOfNum
($allCount , array('ь', 'я', 'ей')); echo $allCount . ' пользовател' . $endWord;
PD9waHAKCmZ1bmN0aW9uIGRlY2xPZk51bSgkbnVtLCAkdGl0bGVzKSB7CiAgICAkY2FzZXMgPSBhcnJheSAoMiwgMCwgMSwgMSwgMSwgMik7CiAgICByZXR1cm4gJHRpdGxlc1soJG51bSUxMDA+NCAmJiAkbnVtJTEwMDwyMCk/IDIgOiAkY2FzZXNbbWluKCRudW0lMTAsIDUpXV07Cn0KCiRhbGxDb3VudCA9IDUxOwokZW5kV29yZCA9IGRlY2xPZk51bSgkYWxsQ291bnQgLCBhcnJheSgn0YwnLCAn0Y8nLCAn0LXQuScpKTsKZWNobyAkYWxsQ291bnQgLiAnINC/0L7Qu9GM0LfQvtCy0LDRgtC10LsnIC4gJGVuZFdvcmQ7