The living, breathing Albert Einstein!

No matter how smart or brilliant we are, we are always breathing to keep ourselves alive. So here's a "breathing" question to ponder about, consider each breath that you take every single moment, approximately how many of the air molecules in the nearest ( order of magnitude ) this breath would also have been breathed by Albert Einstein during his lifetime $1879 - 1955$ ? The atmosphere is about $8 km$ thick and the density of air is about $1 kg/m^3$ . The Earth’s radius is $6.37 × 10^6$ m. You may also assume that the air consists mainly of nitrogen with a molar mass of $28 g$ . Instead of providing the guidelines, try and attempt to make reasonable assumptions for any other data that you may need! To avoid complications, assumptions can be based on ideal situations.