1. Department of Mathematics and Methods of Teaching Math , Volodymyr Vynnychenko Central Ukrainian State University , Shevchenko street 1 , Kropyvnytskyi 25006 , Ukraine
2. Department of Foreign Languages for Mathematical Faculties , Taras Shevchenko National University of Kyiv , 2 / 6 {2/6} , Academician Glushkov avenue , Kyiv 03127 , Ukraine
3. Faculty of Computer Science and Cybernetics , Taras Shevchenko National University of Kyiv , 2 / 6 {2/6} , Academician Glushkov avenue , Kyiv 03127 , Ukraine