my $md5 = ...;

my $lo = 0;
my $hi = 0;
for(split //, $md5)
{
        $lo = $lo*256 + ord;
        $hi = $hi*256 + $lo / 1_000_000;
        $lo = $lo % 1_000_000;
        $hi = $hi % 1_000_000;
}
return $hi.$lo;