Question: What is the middle name of the actress who portrayed the main character in the film based on the first full-length biography of Ayn Rand? 
Sentence (from "Helen Mirren"): Dame Helen Lydia Mirren, {'1': ", '2': ", '3': ", '4': "} ("née" Mironoff; born 26 July 1945) is an English actor.
Relevant evidence: Yes