<?php

fgets(STDIN);
$a=explode(' ',trim(fgets(STDIN)));
$b=array();
foreach($a as $x){
	if(isset($b[$x])){
		$b[$x]+=1;
	}else{
		$b[$x]=1;
	}
}
$c=0;
foreach($b as $x => $y){
	if($y==1){
		$c++;
	}
}
echo $c.PHP_EOL;