No Palindrome

Given positive integers $N$ and $K$, let $S$ denote the **smallest number** of $N$ digits (with no leading zeros) such that: - No substring of $S$ having length **strictly greater** than $K$ is a [palindrome](https://en.wikipedia.org/wiki/Palindrome#Numbers). Find the **sum of digits** of $S$. Note: - A substring of a number is obtained by deleting some (possibly zero) digits from the beginning