Ключевые слова: 1, 2, 3, 4, 5, 6, 7, 8, 9, above, abstract, background, collection, concept, conceptual, eight, five, flat, four, game, gray, grey, group, idea, many, math, multi, nine, nobody, numbers, object, one, orange, perspective, random, red, retro, school, seven, several, six, symbols, three, two, wood, wooden, yellow, zero,