Transcript text: Fill in the following contingency table and find the number of students who both do not have a cat AND do not have a dog.
\begin{tabular}{|l|l|l|l|}
\hline Students & have a dog & do not have a dog & Total \\
\hline have a cat & & & 49 \\
\hline do not have a cat & 20 & & 46 \\
\hline Total & & 50 & \\
\hline
\end{tabular}
Provide your answer below: $\square$