Canada's Prime Minister Stephen Harper (R-L), his wife Laureen, Prime Minister-designate Justin Trudeau and his wife Sophie Gregoire talk at a ceremony to commemorate the October 2014 attack on Parliament Hill, at the National War Memorial in Ottawa, Canada October 22, 2015. The event also honoured the lives of Warrant Officer Patrice Vincent and Corporal Nathan Cirillo, two soldiers killed in a pair of separate attacks police said were carried out independently by radical recent converts to Islam. REUTERS/Patrick Doyle