1. Ramanujan Institute for Advanced Study in Mathematics, University of Madras, Chennai 600005, India
2. Guru Nanak College (Autonomous), University of Madras, Chennai 600042, India
3. Department of Mathematics, St. Joseph University, Chümoukedima 797115, India
4. Institute of Control Systems, National Academy of Science, Baku, AZ 1141, Azerbaijan
5. Department of Informatics and Networks, Faculty of Informatics, University of Debrecen, 4032 Debrecen, Hungary