sub Eratosthenes_Sieve($){
for(@a=(1)x($_[0]+1),$p=2;
$p**2<=$_[0];){for($j=2*$p
;$j<=$_[0];$j+=$p){$a[$j]=
0}for($a[++$p]){}}grep {$a
[$_]}(2..$#a)}