Canadian Prime Minister Justin Trudeau (3rd L), his wife his wife Sophie Gregoire (L) and son Xavier (2nd L), (From 4th L) French President Francois Hollande (4th L), Governor General of Canada David Johnston (5th L), his wife Sharon (3rd R), Britain's Charles, Prince of Wales (4th R), Britain's Prince William, Duke of Cambridge (2nd R), and Britain's Prince Harry (R) pose as they visit the Canadian National Vimy Memorial in Vimy, near Arras, northern France, on April 9, 2017. REUTERS/Philippe Huguen/POOL