$(6)$

char Mat$[5][2]=\{\begin{array}{cc}{A}^{\text{'}},& B^{\text{'}}\\ A^{\text{'}},& C^{\text{'}}\\ O^{\text{'}},& {?}^{\text{'}\text{'}}\end{array},$

$\{$:$\{O^{\text{'}},R^{\text{'}}\},\{M^{\text{'}},N^{\text{'}}\}\}$;

for $($int $r=3$;$r<mn\; id="EditorElement\_163576">5</mn>$;$r++)$

for$($int $c=0$;$c<mn\; id="EditorElement\_163526">2</mn>$;$c++)$

cout $$ Mat $[r-c][c]$;