Question

-20-{-4-[-8+(12-6-2)-2+3]}

Answer 1

-20-{-4-[-8+(12-6-2)-2+3]}   
-20 -{-4-[-8+4-2+3]}   
-20 -{-4-[-8+4-2+3]}   
-20 -{-4-[-4-2+3]}
-20 -{-4-[-6+3]}
-20 -{-4-[-3]}
-20 -{-4+3}
-20 -{-4+3}
-20 -{-1}
-20 +1
-19