AMC 12 2017b Problem 11

Call a positive integer $monotonous$ if it is a one-digit number or its digits, when read from left to right, form either a strictly increasing or a strictly decreasing sequence. For example, $3$, $23578$, and $987620$ are monotonous, but $88$, $7434$, and $23557$ are not. How many monotonous positive integers are there?

\textbf{(A)}\ 1024 \textbf{(B)}\ 1524 \textbf{(C)}\ 1533 \textbf{(D)}\ 1536 \textbf{(E)}\ 2048