Two Polish nuns look at people bathing as hundreds of thousands of young Catholic pilgrims attending World Youth Day (WYD) start gathering at Copacabana beach in Rio de Janeiro for a prayer vigil with Pope Francis, on July 27, 2013. In a speech to Brazil's political, religious and civil society leaders earlier, Pope Francis said a 'constructive dialogue' was needed to confront the country's social turmoil, referring to the massive street protests that rocked Brazil last month to demand an end to corruption and better public services.