1. North-Caucasus Center for Mathematical Research, North-Caucasus Federal University, 355017 Stavropol, Russia
2. Computer Science Department, University of Potsdam, 14469 Potsdam, Germany
3. Computer Science Department, CICESE Research Center, Ensenada 22800, Mexico
4. Control/Management and Applied Mathematics, Ivannikov Institute for System Programming, 109004 Moscow, Russia
5. School of Computing, Communication and Business, Hochschule für Technik und Wirtschaft (University of Applied Sciences for Engineering and Economics), 10318 Berlin, Germany
6. Informatics and Computer Engineering Department, South Ossetia State University, 100001 Tskhinvali, Russia