Beautiful Subsequence

An array $A$ consisting of $N$ integers is called *$K$-beautiful* if it holds the following property: The number of adjacent indices with different values is at most $K$. More formally, there are at most $K$ indices $i$ ($1\le i\lt N$) such that $A_i\ne A_{i+1}$. Note that according to this definition, if an array $A$ is $K$-beautiful, then $A$ is also $(K+1)$-beautiful. You are given an array $A