tl;dr: A classic math puzzle asks you to express any integer using exactly four 2s and mathematical operations, with difficulty scaling from elementary (basic arithmetic) to advanced (Gamma functions, complex numbers). Paul Dirac "ruined" the puzzle in the 1920s by finding a general solution using nested square roots and base-2 logarithms that works for any integer. His formula technically uses three 2s, but can be padded to four by substituting 2/2 for one digit.