Total number of aromatic compounds among the following compounds is ______.

Total number of unpaired electrons in the complex ions $$[\mathrm{Co}(\mathrm{NH}_3)_6]^{3+}$$ and $$[\mathrm{NiCl}_4]^{2-}$$ is ________.

The total number of carbon atoms present in tyrosine, an amino acid, is ________.

The number of optically active compounds from the following is _________.