In regular SMILES, cycles are described using a pair of corresponding 'ring closure symbols', a single digit or a percent sign followed by two digits. We propose an alternative syntax that eliminates the symbol that occurs first in the SMILES string (the ring-opening symbol) and replaces the second symbol (the ring closing) by a ring size (using %N for double digits and %(N) for ring sizes greater than 99). Since the successive atoms in a SMILES string occur in depth-first traversal order and thus form a tree, for any atom there is a single path back to the first atom; thus the ring size can be used as a distance along that path to unambiguously identify the location of the ring opening.