In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Context: After the winter of 1919 Ilmarinen was laid up until she was returned to the Soviet Union according to the Treaty of Tartu. Link Information: The treaty confirmed that the Finnish-Soviet border would follow the old border between the autonomous Grand Duchy of Finland and Imperial Russia. Question: WHich countries participated in the Treaty that returned Silatch to the Soviet Union?
Answer: Russia