I'm filing out an application form on a US website. The website is asking for my first name and last name. The Arabic name system is probably different from the English one. My name as it exactly appears on my national ID is Sara Adel Mahmoud Gad. My first name is Sara, my father's name is Adel, my grandfather's name is Mahmoud, and my family name (which is probably my great grandfather's name) is Gad. The part Adel Mahmoud Gad is shared among the family members, so my brother's name is Ali Adel Mahmoud Gad. Now What is my last name? Is it Gad? Or is it Adel Mahmoud Gad?
There has also been times when websites ask about middle name. What is my middle name? Is it Adel, or Adel Mahmoud? Or do I not have a middle name at all?