a South Asian University, Delhi, India
b Steklov Mathematical Institute, Russian Academy of Sciences, Moscow, 119991 Russia
c Computing Center, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk, 680000 Russia
Correspondence to: *e-mail: stepanov@mi.ras.ru
Received 8 August, 2018
DOI: 10.1134/S106456241807027X