<?php $N = trim(fgets(STDIN)); $A = explode(" ", trim(fgets(STDIN))); $array = array(); for($i = 0; $i < $N; $i++) { $n = $A[$i]; if(array_key_exists($n, $array)) { $array[$n]++; } else { $array[$n] = 1; } } $ans = 0; foreach($array as $key => $value) { if($value == 1) $ans++; } print($ans); ?>