Answer the following Q with stream of consciousness. Context: In the United States of America, the quantity of cigarettes in a pack must be at least 20. Certain brands, such as Export As, come in a pack of 25. For many years, half-packs of 10 (or even 14) cigarettes were commonly available.

Question: how many cigarettes in a pack in the us?
The relevant sentence in the passage is: In the United States of America, the quantity of cigarettes in a pack must be at least 20. Therefore, the final answer is at least 20.