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MathNet 2023-part-03 — 191 problems (EN–VI) Question 111

Math Olympiad Vault · MathNet 2023-part-03 — 191 problems (EN–VI)

Question 111

Let $A$ be a set of functions defined for integers from $1$ to $2023$ and taking integer values from $1$ to $2023$. Suppose that $A$ satisfies the following two conditions:
* For any function $f$ belonging to $A$ and any integers $x$ and $y$ with $1 \le x \lt y \le 2023$, we have $f(x) \ge f(y)$.
* For any functions $f$ and $g$ belonging to $A$ and any integer $x$ from $1$ to $2023$, we have $f(g(x)) = g(f(g(x)))$.
In this case, find the maximum possible number of elements of $A$.