n_skills = 5;
n_workers = 9;
has_skills = [{1, 4}, {5}, {3}, {2, 4, 5}, {4}, {2, 3, 5}, {2, 3, 5}, {5}, {2, 3}];
n_tasks = 20;
d = [4, 4, 3, 2, 3, 2, 3, 2, 2, 5, 3, 4, 3, 2, 1, 3, 4, 1, 4, 2];
rr = [| 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
      | 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 0
      | 0, 1, 2, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
      | 1, 0, 0, 1, 2, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0
      | 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1 |];
suc = [{6, 8, 9}, {5, 7, 14}, {4, 14}, {5, 7, 16}, {12, 13}, {18, 20}, {8, 17, 20}, {13, 19}, {10, 13}, {11}, {12, 14}, {17}, {18}, {15, 18}, {16, 17, 20}, {19}, {19}, {}, {}, {}];