Презентація проблеми

https://drive.google.com/open?id=1xsCuLUQVDwlU-wO_pkBTcxRo2Emj3Tfp 
https://drive.google.com/file/d/1r1nBQikQGJI0yEvKYhKZTDiRKvn_msD-/view?usp=sharing