Balanced Suffix

You're given a string $S$ of length $N$ and an integer $K$. Let $C$ denote the **set** of all characters in $S$. The string $S$ is called *good* if, for **every** *suffix* of S: - The difference between the frequencies of any two characters in $C$ does not exceed $K$. In particular, if the set $C$ has a single element, the string $S$ is *good*. Find whether there exists a rearrangement of $S