What is the main conflict in Papillon by Henri Charriere?

Henri Charriere, known as Papillion for his butterfly tattoo, is accused of murdering a "pimp and stool pigeon" and finds himself in court awaiting the trial. Despite his attorney's assurance that there is no real evidence, he is found guilty and sentenced to life in prison. Papillion is immediately faced with a decision. He has to almost immediately make a decision whether to appeal the sentence, Papillion decides that he will focus everything he has on escape rather than trying to get a new trial to have the sentence reversed or lessened, fearing that he would be sentenced to many years in prison regardless and would then be faced with the need to escape anyway.