In this grid of numbers, what is the missing number (in place of the question mark)?
$$\begin{array}{|c|c|}\hline2&7\\\hline8&9\\\hline\end{array} \begin{array}{|c|c|}\hline0&3\\\hline5&6\\\hline\end{array} \begin{array}{|c|c|}\hline0&11\\\hline10&11\\\hline\end{array} \begin{array}{|c|c|}\hline2&?\\\hline4&3\\\hline\end{array}$$