Child born in June 2020 but only stayed in US until Oct 2020. What should I input for the number of months in the US?

Two questions were asked for newborn: How many months did the baby live with me and how many months in US. As per Turbotax suggestion, I used the whole year for the period baby lived with me since born in 2020. Not sure what should be the input for the number of months in US.