Ключевые слова: brain, brain teaser, complex, complexity, connection, difficulty, enigma, equation, find a solution, hard, impossible, insoluble, intelligence, interrogation, investigate, investigation, join, logic, look for a solution, make ends meet, mystery, obstacle, optical illusion, overcome an obstacle, overcome difficulties, problem, reflect, reflection, science, silhouette, solution, solve a problem, to find, to look for, to wonder,