High density living demands cooperation and courtesy for it to work well. Smoking is an issue of particular sensitivity. While every resident has the right to smoke on their lot without judgement or penalty, it is helpful to consider the comfort and wellbeing of your neighbour.
Smokers, you can be considerate without giving up your right to smoke.
Non-smokers, try talking to your neighbour before getting angry. They may be unaware they are bothering you.
See if there is a way that both parties needs can be met.
Kindness and communication is the key.