We use common format for SATs - DIMACS.
This is an example of comment line.
c comment line
CNF starts with headline p cnf [number of variables] [number of clauses].
Next [number of clauses] lines consist of clauses where variables are indexed
from one and could be positive or negative (i.e. negation of variable). Clauses input ends with 0.
p cnf 3 2
1 -2 0
2 3 0