ABCD\begin{array}{|l|l|} \hline A & B \\ \hline C & D \\ \hline \end{array}ACBD
ACBD\begin{array}{|l|l|} \hline A & C \\ \hline B & D \\ \hline \end{array}ABCD
ABCD\begin{array}{l|l} A & B \\ \hline C & D \\ \end{array}ACBD
ABCD\begin{array}{} A & B \\ C & D \\ \end{array}ACBD