On June 1, 1922, in Helsinki, Finland and Soviet Russia signed an Agreement between RSFSR and Finland about the measures providing the inviolability of the Soviet-Finnish border. Both parties agreed to reduce the number of border guards and to keep those who do not reside permanently in the border zone from freely crossing the border from either side to the other. Towards the end of the uprising some 30 000 East Karelian refugees evacuated to Finland. The Karelian Worker's Commune was renamed into the Karelian Autonomous Soviet Socialist Republic in 1923, and its autonomy was further expanded. However the cultural autonomy practically ended in 1933 - 1935 when the émigré Finnish leaders Edvard Gylling and Kustaa Rovio were purged and teaching of Finnish language was prohibited.  Gylling had promoted the adoption of Finnish rather than Karelian within the KASSR as he and the other émigré Finns who dominated the leadership of Karelia prior to 1935 did not consider Karelian to be anything more than a rustic dialect of Finnish.  It may also be argued they held the same view of the essential unity of the Karelians and Finns as one Finnic people as their nationalist counterparts, and also wished that they be unified .
Who agrteed to reduce the number of border guards?
RSFSR and Finland