I will close market at a random point between tomorrow and 2035. Then I will wait 10 days and contact my russian friends to get the info: at which currency exchange rate they can BUY Euro in their local banks.
After the start of the war and mobilization there were several artificial limitations on trading Euros in Russia, and because of that the rate inside the country can differ much from the outside.
The market opens at 102, because to buy 1 euro they had to pay 102 rubles today. Note that this number is not pure number from stock exchange, it includes bank margin (which also grows). If I notice that the rate is different (>1rub difference) in different banks, I will pick 3 most influential russian banks/services situated in Moscow (who offer Euros at the moment for resolution) and find the average.
If buying Euros on bank account becomes forbidden, then the market automatically turns into "cash exchange predictor".
After this market resolves there will another one identical be opened, to allow for continued prediction.