Gurobi 5.6.3 (linux64) logging started Wed Oct 8 06:50:56 2014 Optimize a model with 60271 rows, 60270 columns and 180320 nonzeros Presolve time: 1.65s Presolved: 60271 rows, 60270 columns, 180320 nonzeros Variable types: 0 continuous, 60270 integer (60270 binary) Found heuristic solution: objective 31.7043432 Root relaxation: objective 1.554146e+01, 3208 iterations, 0.56 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time * 0 0 0 15.5414571 15.54146 0.00% - 2s Explored 0 nodes (3208 simplex iterations) in 2.38 seconds Thread count was 1 (of 16 available processors) Optimal solution found (tolerance 1.00e-04) Best objective 1.554145705444e+01, best bound 1.554145705444e+01, gap 0.0%