Hi.  I appreciate your concern.  As per your question ,effects of smokig cigarettes  depends on person to person's immunity age and sex. Tobacco smoke is enormously harmful to your health. There’s no safe way to smoke. .
Cigarettes contain   hundreds of ingredients. When they burn, they generate thousands of  chemicals, . Many of those chemicals are poisonous that can cause cancer. .     carcinogens, toxins, and tar are products that left behind when cigarette is burnt....these biproducts effects all the systems in our body from digestive to reproductive  system.One of the product formed in a burning  cigaretteis 
nicotine which is a nerve stimulater and boosts up your energy level just for some time. Due to this you go on addicting to it. Cigarette smoker is at greater risk in development of mouth and 
throat cancer,gums diseases.         
Smoking person is also at a greater risk in  development of 
diabetes,blood pressure,stroke and 
heart attack,coughing  and asthma due to irritants produced......so wether 1 or 2 its never going to help you in any way.It will always decrease your level of immunity.You should quit this habit not abruptly but slowly  which will may cause irritability,
dizziness,
headaches and sleep problem but not to worry .it will slowly go away as you get involved in other things.I am sure my information helps you.