If you treat it as a gift, then you need to file a form 709 gift tax return. There is no gift tax owed unless your lifetime gifts given is more than $5 million, but you have to fill out the form to report it. Then, when they give you the money back, you will have to file a separate report for receiving a gift from a foreign person of more than $100,000. Again, no tax is owed, just the reports. https://www.irs.gov/businesses/gifts-from-foreign-person
Or, if you treat it as loan, you don't have to file either gift report. But, the IRS expects business transactions such as loans, to be handled in a businesslike manner and that requires charging interest. If you don't charge your parents interest, you will still be required to report "imputed interest" -- the income you would have received if you charged the IRS minimum interest rate (currently an APR of 1.18%).
Neither of these requirements will cost you much money, but you should stick with the rules. Your bank will automatically report any transaction of more than $10,000, so it will be good to have a proper paper trail either way. (And don't think about splitting it up into 16 separate transactions of less than $10,000. That's called "structuring" and is a separate crime even if the overall reason for the transactions is perfectly legitimate.)