Ключевые слова: 2, abstract, alphabet, app, application, arrow, button, calculate, calculator, cipher, clean, collection, colorful, design, digit, division, eight, equal, equation, figure, flat, graphic, icon, illustration, image, interface, math, mathematics, media, minimalistic, mobile, modern, multimedia, navigation, number, numeral, paper, school, set, shadow, sign, silhouette, software, sparse, symbol, three, two, web, website,