Let $$A = \left[\begin{array}{cc} -3 &1\cr -3 &3 \end{array}\right],$$ $$B = \left[\begin{array}{cc} 5 &-3\cr 2 &-1\cr 1 &-1 \end{array}\right],$$ $$C = \left[\begin{array}{cc} 2 &3\cr 1 &-3 \end{array}\right].$$ If possible, compute the following. If an answer does not exist, enter DNE.

$A+B =$  help (matrices)

$A+C =$  help (matrices)