Father of my father: Francisco Perez Gonzalez....Francisco was chosen at caprice, but Perez is first surname of his father, and Gonzalez is first surname of his mother.
Mother of my father: Rosario Barrera Raya. Rosario is chosen at caprice, Barrera is first surname of her father, Raya is first surname of his mother.
Then: Name of my father: Antonio (chosen at caprice) Perez Barrera, because Perez is the first surname of his father and Barrera is the first surname of her mother.