Construct An Array

You are given a positive integer $M$ and an array $A \ (1 \leq A_i \leq M)$ consisting of $N$ positive integers. Construct an array $B$ of length $N$ such that: - $1 \leq B_i \leq M$ for all $1 \leq i \leq N$; - For all $1 \leq i \leq N$, there does not exist an index $1 \leq j \leq i$ such that the frequency of $B_j$ is more than that of $A_i$ in the subarray $[B_1, B_2, \ldots, B_i]$ It can be