The keys were left in the nearby shop, and the shop owner initially didn't understand what keys I was talking about. After I received the keys and entered the block, there were two stepladders with the same numbers, and the instructions didn't mention which way to go (you need to go to the right).
In the kitchen, there was various cookware and a coffee machine, but only two decaf capsules and no salt or vegetable oil. So if you want to cook, go and buy a month-worth supply of salt and oil for your 3-day stay.
Other than that, our stay went great. The apartment is spacious, comfortable, clean, and warm in the winter, situated in a nice neighborhood, close to public transit, and within walking distance of the city center. At night it was quiet, with the exception of a garbage truck that comes before to midnight.
So, now you know that you should ascend the RIGHT ladder, so this place would be a great choice for the price.