$$\left. \begin{array} { l } { ( - 54 - 42 ) \div \{ 9 + ( - 5 \times - 8 ) \div 4 - 3 \} } \\ { 10 - [ 8 - \{ 2 - ( 7 - 9 + 2 - 3 ) \} ] } \end{array} \right.$$
