How to report a $100 interest from a foreign bank account

I am Alien resident in the US, my only income in 2016 was from Brazil. I am a certified physician in Brazil and I worked  from August to December there. I also have a bank account with money in Brazil (since 2007) and I got $100 in 2016 from the bank as an interest because I have my money in the bank. I have had trouble to report this $100, I do not know where to report it and how to complete the boxes with form and line, schedule and line.