This is X.  Now it is $latex \begin{array}1 & 2 \\3 & 4\end{array}$.

\displaystyle \left.  \begin{array}  \fbox{1} & \fbox{1} & \fbox{1} & \fbox{2} & \fbox{3} & \fbox{3} \\  \fbox{2} & \fbox{2} & \fbox{2} & \fbox{3} & & \\  \fbox{3} & \fbox{3} & & & &  \end{array}  \right.