How can I search for similar sentences in meaning?

Need algorithm/library for searching similar sentences in Russian.
Conventionally, in the database there is question-answer. Need to find the nearest in meaning to the sentence and answer it.
The context must be considered, responses must be fast: 1-3 seconds.
What to use: word2vec, search somehow keyword?
April 3rd 20 at 18:33
1 answer
April 3rd 20 at 18:35
Solution
  1. Using word2vec, the resulting vector for each word
  2. For each response consider a vector as an average of vectors of words of which it consists
  3. Consider the vector question, as an average of vectors of words of which it consists
  4. For a particular question looking for an answer using, for example, cosine distance

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