9 - a
6 -b
1 - c
4 - d
7 - e
10 - f
12 -g
11 - h
3 - i
8 - j
2 - k
5 - l
a+b+c+d+e-f-g+h+i+j-k+l=30
9+6+1+4+7-10-12+11+3+8-2+5=30
9 - a
6 -b
1 - c
4 - d
7 - e
10 - f
12 -g
11 - h
3 - i
8 - j
2 - k
5 - l
a+b+c+d+e-f-g+h+i+j-k+l=30
9+6+1+4+7-10-12+11+3+8-2+5=30