@files = grep /^output\d+$/, <output*>;
foreach $file (@files) {
open (IN, "<$file");

while ($input = <IN>)
{
print "$file\n";

($x, $y, $z, $sum) = split (/\s+/, $input);
$total += $sum;
$i++;
$div = $total/$i;
$sqrt = sqrt($div);
print "$total\n";
open (OUT2, ">RMSD$file");
print OUT2 $sqrt;
}
}