If i have both short term and long term excess losses, do I have to allocate either loss first in my $3000 deduction against income? Is it Pro Rata? Does it matter?

My 2016 taxes had a short term capital loss of less than $3000 and a long term capital loss of more than $3000.  Can I allocate the $3000 which went against income to the long term portion of my losses and carry over the short term portion?