c  ----------- DIMACS Challenge - CNF format -----------
c
c  TRISAT Generator (Pretolani 1990)
c
c                  (Even) number of nodes ==>    4
c        Charge ( 0 = sat. / 1 = unsat. ) ==>    1
c  Horn Percentage (min -> 25; max -> 75) ==>   25
c      Number of  Propositional variables ==>    6
c                       Number of Clauses ==>   16
c                   Nodes with Charge = 1 ==>    1
c                 Horn Percentage (exact) ==> 0.000
c
c  -----------------------------------------------------
p cnf    6   16
     -3      -2      -1 0
      3       2      -1 0
      2       1      -3 0
      3       1      -2 0
     -5      -4      -1 0
      5       4      -1 0
      4       1      -5 0
      5       1      -4 0
     -6      -4      -3 0
      6       4      -3 0
      4       3      -6 0
      6       3      -4 0
      6       5       2 0
      6      -5      -2 0
      5      -6      -2 0
      2      -6      -5 0
0