Separate file photos of Roman Catholic clergy from Latin America cited as being possible candidates to be the next Pope, (L-R) Brazilian cardinal Joao Braz de Aviz, Sao Paulo Archbishop Odilo Scherer, and Argentine cardinal Leonardo Sandri, taken in Rome between 2007 and 2012. Pope Benedict shocked the world on Monday by saying he no longer had the mental and physical strength to cope with his ministry, in an announcement that left his aides "incredulous" and will make him the first pontiff to step down since the Middle Ages. He will step down on February 28 and the Vatican expects a new Pope to be chosen by the end of March. REUTERS/Alessandro Bianchi (ITALY - Tags: RELIGION POLITICS TPX IMAGES OF THE DAY)