media-share-0-02-05-ccad8497e1db754a608a3a2bd96397daa49dffbdd8003d505868bee53ab0edf9-639fc9bb-3719-4bbe-b14c-71efe4dfa6f9 Published 13/12/2018 at 960 × 1280 in Математика без граници – Есен 2018г.