1. St. Petersburg Academic University 1 , Khlopina, 8/3A, St. Petersburg 194021, Russia
2. Peter the Great St. Petersburg Polytechnic University 2 , Politekhnicheskaya 29, St. Petersburg 195251, Russia
3. St. Petersburg State University 3 , Universitetskaya Emb. 13B, St. Petersburg 199034, Russia
4. Skolkovo Institute of Science and Technology 4 , Nobelya str. 3, Moscow 121205, Russia