p cnf 31 71
c 3 i
c 4 h
c 5 f
c 6 g
c 9 b
c 10 a
c 14 d
c 15 c
c 19 e
3 4 0
-3 -4 0
4 3 0
-4 -3 0
26 -4 0
-26 4 0
6 -5 0
-6 5 0
27 -6 0
-27 6 0
7 0
8 -9 0
-8 9 0
20 -7 0
-20 7 0
10 -20 21 0
-10 20 0
-10 -21 0
21 10 0
-21 -10 0
9 -20 22 0
-9 20 0
-9 -22 0
22 9 0
-22 -9 0
28 -10 0
-28 10 0
29 -9 0
-29 9 0
12 -10 -9 0
-12 10 0
-12 9 0
13 -11 12 0
-13 11 0
-13 -12 0
-7 13 0
23 -8 0
-23 8 0
14 -23 24 0
-14 23 0
-14 -24 0
24 14 0
-24 -14 0
15 -23 25 0
-15 23 0
-15 -25 0
25 15 0
-25 -15 0
30 -14 0
-30 14 0
31 -15 0
-31 15 0
17 -14 -15 0
-17 14 0
-17 15 0
18 -16 17 0
-18 16 0
-18 -17 0
-8 18 0
19 0
-1 0
-2 0
-5 26 27 0
5 -26 0
5 -27 0
-11 28 29 0
11 -28 0
11 -29 0
-16 30 31 0
16 -30 0
16 -31 0