Definition: Given a document, generate a short title of the document. The title should convey the main idea/event/topic about which the document is being written. Note that URLs in the text have been replaced with [Link].
Input: Image copyright Getty Images Image caption  Prime Minister of Canada Justin Trudeau  departs a press availability at the Canadian Embassy in Washington
In 2017   Canadian Prime Minister Trudeau  learned a lesson about the power of social media.
 Trudeau 's January tweet "isn't necessarily the sentiment being held by a lot of Canadians".
 Mr Trudeau  ended 2017 in an ethics quagmire partly of  his  own making.
Meanwhile   Trudeau 's finance minister  Bill Morneau  is struggling with his own ethics troubles.
A mid-December poll by the Angus Reid Institute indicated that for the first time since his election   Trudeau 's approval ratings had dropped below 50%.
 Trudeau 's ratings are still strong for a politician  but Kurl says there is "perhaps a little bit less adoration and a little bit more exasperation with the prime minister".
As the two rival leaders find their feet - and if  Trudeau  and  his  ministers keep handing them easy ammunition - 2018 could also prove a rough ride.

The tests facing Canada's PM Justin Trudeau in 2018