回複：一道算術題和幾個字迷: 秋 告 口

There are 5 odds and 4 evens. So, one odd number should be eliminated first, the 括號 can do this, like: change 2+1 to 2(-1)=-2

by trial and error, we have:

9-8 -7+6 -5+4 +3 +2(-1)=0


秋 告 口