Russia's President Dmitry Medvedev (2nd R, back) and his wife Svetlana (R, back) attend an Orthodox Christmas Mass at the Christ the Saviour Cathedral in Moscow late on January 6, 2012. Russia celebrates Christmas on January 7 according to the Julian calendar that is used by the country's Orthodox church. REUTERS/Sergei Karpukhin (RUSSIA - Tags: RELIGION POLITICS)