V.V. Melentiev1, D.V. Serdechnyi2, P.V. Nikitin3, S.A. Korchagin4

1 Engels Institute of Technology (branch) of Yuri Gagarin State Technical University of Saratov (Engels, Russia),

2−4 Financial University under the Government of the Russian Federation (Moscow, Russia)

1 melen2004@inbox.ru, 2dvserdechny@fa.ru, 3pvnikitin@fa.ru, 4sakorchagin@fa.ru