Equal Median

You are given a sequence of integers $A_1, A_2, \ldots, A_N$. You should process $Q$ queries. In each query: - You are given two integer parameters $id$ and $v$. - Change the value of $A_{id}$ to $v$. - Then, consider all ways to partition the sequence $A_1, A_2, \ldots, A_N$ into multisets $M_1, M_2, \ldots, M_K$ (for an arbitrary $K \ge 1$) such that: - Each element of $A$ is assigned to exa