open IN,"<$input";
open OUT,">./$output/Molekuehl$i.sdf";
while (<IN>){
$j=0;
if ($_ eq "\$\$\$\$"){
$i++;
close OUT;
open OUT,">./$output/Molekuehl$i.sdf";
$j=1;
}
if ($j==0){
print OUT "$_\n";
}
}
close IN;
close OUT;