atoms Hydrogen?

Are there unused atoms other than Hydrogen ?

can the central atom make one more bond?
choose the non-H atom that is next in line to be able to make the most bonds. attempt to connect the said unused non-H atom to the central atom via a SINGLE BOND recalculate T:
remove 2 electrons from T to account for one used bond.
continue
  all you are left with is Hydrogens.

continue
  is there a "terminal" atom in the skeleton that can make one more bond?   use this terminal atom to make a SINGLE BOND with the unused non-H atom above.   recalculate T, remove 2 electrons from it to account for the above bond continue  
 
    continue