Poland's Prime Minister Beata Szydlo, leader of the Law and Justice party Jaroslaw Kaczynski, Speaker of Parliament Marek Kuchcinski and Polish Interior Minister Mariusz Blaszczak (L-R) pray at a ceremony marking the sixth anniversary of the crash of the Polish government plane in Smolensk, Russia, that killed 96 people on board including late Polish president Lech Kaczynski and his wife Maria, outside the Presidential Palace in Warsaw April 10, 2016. REUTERS/Kacper Pempel