%% Nonogram "difficult"
%% From Gecode
rows = 15;
row_rule_len = 2;
row_rules = array2d(1..rows, 1..row_rule_len,
  [
   0, 3,
   1, 1,
   1, 1,
   1, 1,
   1, 2,
   0, 5,
   0, 1,
   0, 2,
   0, 1,
   0, 1,
   1, 2,
   1, 2,
   2, 1,
   2, 2,
   0, 3
   ]);

cols = 15;
col_rule_len = 2;
col_rules = array2d(1..cols, 1..col_rule_len, 
  [
   0, 3,
   0, 2,
   0, 2,
   0, 1,
   0, 2,
   0, 3,
   0, 2,
   0, 4,
   0, 3,
   0, 4,
   2, 1,
   1, 1,
   1, 1,
   1, 1,
   0, 3
   ]);