Ms. Carr asks her students to read any $5$ of the $10$ books on a reading list. Harold randomly selects $5$ books from this list, and Betty does the same. Find the probability that there are exactly $2$ books that they both select. The answer should be expressed in the form \(\frac{k}{m}\), where the fraction is in simplest form. Please give the value of \(k + m\).

Let's think step by step and output the final answer within \boxed{}.
user