modeling - How to store molecule data using SMILES when building a toy chemistry model -

i'm building toy chemistry model based around gillespie's algorithm. starting food set of {h,o,n,c} let system evolve, have been storing molecules strings in smiles format.

for instance:

[o] reacts [h] --> [o] ([h])  [o] ([h]) reacts [h] --> [o] ([h]) ([h]) 

using square brackets i've been able keep molecules in system consistent smiles interpretation.

however system of storage allowing me construct linear molecules.

how can create, instance, carbon ring, interpreted in smiles ring of carbon atoms, without hydrogen atoms?

for instance c1ccccc1 gives http://www.chemicalize.org/structure/#!mol=c1ccccc1&source=calculate how generate 6 carbon atoms in ring without 12 hydrogen?