Fibonacci number (idea)

$m=1; $k=1;
print "Find the first how many #s: ";
$x=<stdin>;
$y=3;
print "0, ", "1, 1, ";
until ($y>$x) {
    $n=($k+$m);
    print $n, ", ";
    $k=$m; $m=$n; $y++;
}