Question 159
Let $\overline{abcd}$ be a four-digit number, where $ab$ and $cd$ are two-digit numbers. If the sum of $ab$ and $cd$ is equal to $bc$, then $\overline{abcd}$ is called an *interesting number*. For example, $13+18=31$, but $1208$ is not an interesting number because $\overline{08}$ is not a two-digit number. How many interesting numbers are there in total?